1,000 Game Manuals/1000gamemanuals.iso/Odyssey/Computer Intro.txt

Text File | 2001-10-17 | 137KB | 3,382 lines

ODYSSEY2

COMPUTER INTRO
BY MAGNAVOX

Contents

 2. In The Beginning
11. The World of the Computer
20. Creepy Crawler
28. Creepy Crawler Version II
29. The Roll Mode - Your Program Trouble Shooter
30. Addition*Program A
35. Addition*Program B
40. Addition*Program C
46. One Digit Multiplication
52. One Digit Division
62. Area Problems Using "Go to Subroutine" and "Return"
71. One Digit Addition FLash Card
74. Three Ways to Enter and Output a Letter
76. Six Letter Guess
80. Message
87. Operating Mode Review
92. Glossary of Frequently Used Computer Terms
100. Instruction Sets
104. Program Sheets

this gatefold will provide you with an electronic road map - please keep it
open as you work with your Odyssey2 computer

Key Codes

Key    Hex    Decimal
Code   Code   Equivalents
-------------------------
0       00      00
1       01      01
2       02      02
3       03      03
4       04      04
5       05      05
6       06      06
7       07      07
8       08      08
9       09      09
A       20      32
B       25      37
C       23      35
D       1A      26
E       12      18
F       1B      27
G       1C      28
H       1D      29
I       16      22
J       1E      30
K       1F      31
L       0E      14
M       26      38
N       2D      45
O       17      23
P       0F      15
Q       18      24
R       13      19
S       19      25
T       14      20
U       15      21
V       24      36
W       11      17
X       22      34
Y       2C      44
Z       21      32 [incorrect]
Blank   0C      12
:       0A      10
$       0B      11
Clear   2E      46
?       0D      13
.       27      39
+       10      16
-       28      40
*       29      41
./.     2A      42
=       2B      43
Enter   2F      47

Internal Flow

[Illustration shows a box labeled Control Unit, boxes hanging off it labeled
Accumulator, Program Counter, Subroutine Return Address Register, ALU, and
Registers 0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F.  Also, arrows pointing to and from
the Control Unit and three boxes Labeled Memory (ROM) Instructions and
Constants, Keyboard, and Symbol/Sound Generator.  Also, an arrow going from
Symbol/Sound Generator to a box labeled TV Screen.]

Keyboard

[Illustration of the keyboard]

Computer Intro is not for everyone - but if you're up for a rewarding mental
challenge, here is a fascinating entry point into a complex and highly
technical subject.

The cartridge turns your Odyssey2 into a very special kind of computer.  It
won't balance your checkbook or do your incom tax or plot the course of a
spaceship to Mars.

But it will giveyou some idea of how those computers do their work.  You
will begin to understand how a computer "thinks" and even begin to think like
a computer "thinks."

The initial orientation and explanation are deliberately couched in the
most simplistic of terms.  They don't assume anything more on your part than a
working knowledge of basic arithmetic.

After a brief explanation of how computers work and what they are made of -
you will start getting "hands on" experience and will learn by doing.

You will learn how to enter a program - the first stop in learning how to
actually write your own.

The gatefolds in the front and back of the manual provide you with
electronic road maps.  Keep these references in front of you and you will
clearly understand what's going on and how computers really compute.

In The Beginning

In the beginning, there were ten fingers - then a prehistoric Einstein
discovered his toes and man could count up to twenty.

The oldest computing device we know of is the abacus.  It was first used in
China in the sixth century B.C.

The very first digital computer was designed by Charles Babbage in the
1830's.  It was more than a calculator.  Babbage designed it to be
programmable, and it would have been able to perform any arithmetic or logic
calculation.

It was desgined to use punched cards for entering data and instructing the
machine with mathematical commands.

[Illustration shows an abacus. Caption: Chinese Abacus]

[Illustration of a person using an abacus]

[Illustration of a Babbage computer. Caption: Babbage computer]

There were two problems.

Problem one.  Babbage's elaborate drawings called for a building the size
of a Dickensian shoe factory to house his "analytical engine."

Problem two.  Babbagge died before the machine could be built.

The first practical programmable computer was built in a basement at
Harvard University during World War II by IBM.  It weighed 35 tons!

This machine used an exotic combination of electronic, electrical and
mechanical gear to do its arithmetic.  The instruction program was stored on a
punched paper tape that unreeled automatically.  Number were entered into the
machine on a panel covered with 1,440 dials!

The first all-electronic computer was built at the University of
Pennsylvania shortly after the war ended.  ENIAC (Electronic Numerical
Integrator and Computer) was 1,000 times faster than its predecessor.

But it filled a room 30 feet wide and 50 feet long.  Its 18,000 vacuum
tubes were connected by about a half-million soldering points.

Today, everything that ENIAC could do and far more is perfromed by a device
slightly smaller in size.

It is less than one quarter of an inch square - and can make more than one
million electronic decisions every second.  It is called a semiconductor.  It
is possible for one semiconductor in one of its newest forms - the
microprocessor - to account for more than 310 trillion separate functions.

[Illustration of a bunch of gears.  Caption: Detail section of the Babbage
computer]

And this is only the beginning!

If computer technology continues to develop at its present rate, one of
these chips will be able to store about a quarter-million bits (the smallest
unit of computer information) in its memory within a few years.

Ten years from this point, there will be hips capable of rememberin a
million bits of information.

By 1990, the number of logic or decision-making computer circuits on these
one quarter inch chips are expected to number a quarter of a million.

Today's large computers, selling in the one million dollar range and as big
as several filing cabinets, contain only about 10,000 logic circuits and a
main memory capacity of a few million bits.

[Picture of a circuit board]

[Picture of a few buttons, with one lit button labeled READY.  Superimposed is
a green sine wave]

[Picture of a chip, with some forcepts reaching to grab something.]

As microprocessor technology progresses, computers may be developed that
understand human speech.

It is even possible that they can be taught to read handwriting!

The microprocessor in your Odyssey2 is infinitely more sophisticated than
the mathematical marvels that were teh state of the art in the forties and
fifties.

The technology of the microprocessor is unquestionably going to
revolutionize the way the world works - and the way you'll live.  A computer
will control your car's automatic transmission and fuel injection system.

A computer will monitor fire and burglar alarm systems in your home.

The lights in your home will be computerized.  So will the locks on the
doors and windows.

[Picture of another circuit board]

[Picture of a display tube with a hand operating a control on it]

A computer will even water the lawn.

A computer will do your shopping from the house - and pay your bills
without you writing checks.

Computers will simulate three dimensional space for architects to help them
mentally walk around their houses before they're built.

Computers will alert doctors to patient problems that would be
imperceptible under today's circumstances.

Computers will help composers hear their music as they're writing it - even
if it's too complicated for them to play.

Businessmen can have electronic simulations of their companies in their
attache cases.

We are really still just at the very beginning of the computer age.  You
have picked a very good time to get involved.

[Picture of some sort of control panel, with an image of cars on a freeway
double exposed on top of it]

[Picture of a circuit board]

The World of the Computer Is Strange and Wondrous

Computers have already carried man to the moon - to Mars - and far beyond.

They lie at the heart of fearsome weapons systems.

They fly planes - monitor automobile engines - run factories - and even
translate languages.

All of these with the brain power of a good screwdriver.

Congratulations!  You have just completed your first lesson.

You are much smarter than any computer at the present state of the art!

For all of its awesome capabilities, the computer is nothing more than a
rather simple-minded tool.

But once you learn how to use it, you'll have more power at your command
than Julius Caesar ever dreamed of.

A computer has few basic talents.

It can add - and it can move numbers around.

A computer never forgets - and computers don't make mistakes.  (If a
computer churns out misinformation, there's a mistake in the program.
Computers are utterly faithful in following instructions.)

Big deal.  Computers can't multiply, divide, or even subtract the way you
do.  But what a computer does do, it accomplishes with absolutely astonishing
speed.

Your Odyssey2 can make over 100,000 electronic decisions every second - and
there are computers around that are more than ten times faster than that!

To multiply, Odyssey2 simply adds number together at an incredible speed.
To subtract, it moves numbers around in a special way so that adding them
together will give the correct answer.  This sounds like doing it the long way
- but when you're that fast at addition, the juggling act becomes worthwhile.

It's not all that hard to talk with a computer.  It only understands two
words.  Yes - and no.  Yes - means that an electrical pulse is tickling the
computer's sensitivities.  No - means that no electrical pulse is going
through.

The symbol for "yes" in computer language is 1.

The symbol for "no" is 0.

Once you have memorized 0 and 1, you have memorized the entire alphabet of
the only language computers speak in any country of the world.

This is called a binary system because there are only two symbols involved.

It's sort of a code.  Here's the key.

Binary Numbers and Their Decimal Equivalents.

1=0001  5=0101  9=1001  13=1101
2=0010  6=0110 10=1010  14=1110
3=0011  7=0111 11=1011  15=1111
4=0100  8=1000 12=1100  16=0001 0000


Letters of the Alphabet and Their Binary Code Equivalents.

Keyboard
Letter     Binary      Decimal Hexidecimal

A          0010 0000   32      20
B          0010 0101   37      25
C          0010 0011   35      23
D          0001 1010   26      1A
E          0001 0010   18      12
F          0001 1011   27      1B
G          0001 1100   28      1C
H          0001 1101   29      1D
I          0001 0110   22      16
J          0001 1110   30      1E
K          0001 1111   31      1F
L          0000 1110   14      0E
M          0010 0110   38      26
N          0010 1101   45      2D
O          0001 0111   23      17
P          0000 1111   15      0F
Q          0001 1000   24      18
R          0001 0011   19      13
S          0001 1001   25      19
T          0001 0100   20      14
U          0001 0101   21      15
V          0010 0100   36      24
W          0001 0001   17      11
X          0010 0010   34      22
Y          0010 1100   44      2C
Z          0010 0001   32[BAD] 21


Working with endless daisy chains of 0's and 1's would be more than tedious
for the human brain - but the computer is really good at it.

The inside of a computer is mainly a series of little electronic gates.  0
- the absence of an electrical pulse - leaves the gate open.  1 - the presence
of an electrical pulse - closes the gate.  And remember - the electronic gates
in your Odyssey2 computer are opening and closing at the rate of 100,000 times
every second.

You will enter programs in your Odyssey2 through either the hexidecimal or
assembler language (these will be explained later).  The Odyssey2 will then
change the data and instruction sets entered into binary language (1's and
0's) and store that information in the Memory and in the registers.

The actual computing is done by the computer's Central Processing Unit
(CPU).  The CPU in your Odyssey2 is composed of the Accumulator (a working
register which stores data temporarily); the Program Counter (a working
register which locates and identifies the instruction sets and keeps them in
order); the Registers (in which data, implemented by the programmer, is
stored); the Sub-Routine Return Register (which is used with a certain
instruction set); the Arithmetic Logic Unit (ALU); and the Control Unit.

The Control Unit directs the flood of electronic traffic traveling through
the computer and controls the data flow between the different components of
the computer.  For example, it regulates the flow of information bweteen the
Memory and Arithmetic Logic sections and also orders processeddata to move
from the Memory to the Output terminal.  The Output terminal of your Odyssey2
computer is the screen of your television set.

The Arithmetic Logic Unit is where the computer teaches numbers to tap
dance.  Its nickname is "number cruncher."  It acts on the binary data fed
into the computer's memory and registers - and then changes them according to
the programmed instructions.

Now, you're ready to learn by doing.  You're going to enter a program into
your computer.  Open the fold-out at the front of the book and you'll see what
happens to everything along the way.

Important point.  The neat thing about computers is that they will always
follow your instructions with unflagging good faith.  The dumb thing about
computers is that they will only do what you have instructed them to do.

It's very important to make sure that you enter every step and do it right.
If you make an error, the computer is going to make an error.

Be sure that the power to your Odyssey2 console is turned off.  Insert the
COMPUTER INTRO cartridge into the console.  Be sure the label side is facing
the alpha-numeric keyboard.  Now, turn on the power.

You're going to be talking with your Odyssey2 computer through the
keyboard.  It will talk back to you over your television screen.

[Illustration of the Odyssey2 keyboard]

Let's take a brief trip around the keyboard.  It has forty-eight keys.
Each key has been encoded in the computer languages we're going to be using.
You'll find this code on the gatefold at the front of the book.

The keyboard also contains some surprises - four games that have been
pre-programmed in the cartridge.

Press 2 on the alpha-numeric keyboard.  A FLASH CARD addition game will
appear on your television set.  An unsolved addition problem flashes on your
screen.  You enter the solution through the keyboard.  If the answer is less
tha 10, preface the number with a 0. (Important!  Always use the numeral 0 at
the top of the keyboard when entering a 0.)  If you give a wrong answer, an
angry NO will appear on the screen.  If you give a correct answer, it will
appear in its proper position.  To bring another problem to the screen, summon
it from the computer by pressing any key.


Adding numbers is no big deal until you see how many addition problems you
can solve in one minute.  If you keep trying to beat your own record or
another player, you can't help but sharpen your skills.

Press RESET, then press 3 on the alpha-numeric keyboard and you're into
COMPUTER TELEPATHY!  It's a high-low game.  The computer secretly chooses a
number between 00 and 99.  The secret number won't appear on the screen - but
a question mark will.  You make a guess at the correct number and enter it
into the computer.  Your guess will appear on the screen.  It will be followed
by an H if it is higher than the computer's secret number - or an L if it is
lower.  If you guess correctly, the nuber will be followed by an X.  Play
against an opponent and see who can guess the computer's secret number in the
fewest number of guesses.

Now, press RESET, then press 4 on the alpha-numeric keyboard.  BETWEEN THE
SHEETS appears on the screen.  You'll see three sets of numbers.  Example: 03
07 00.

The first two numbers are the sheets.  The computer has thought of another
number which it is keeping to itself.  The last number is your score.  If you
think the computers secret number is between 03 and 07 press YES on the
alpha-numeric keyboard.  If you don't think it falls between 3 and 7, press
NO.  If you are correct, you score a point and the number will apear between
the 3 and 7.  If you are wrong, the computer rewards you with a couple of
BEEPS right in the ear and your score remains the same.

Press RESET, then press 1 and a series of blocks appears on the screen.
The blocks flahs in random order and ar accompanied by a buzzing sound.  We
call this spooky effect "THE CREEPY CRAWLER."  You can call it anything you
want.

We can re-program The Creepy Crawler to display other symbols on the
screen.  There is a large selection of graphics in the memory of your
Odyssey2.  You'll find the complete collection in the fold-out at the back of
the book.

The Creepy Crawler program is quite short and represents a good starting
point.  We're going to follow this and succeeding programs with a sort of road
map so you can see where your input goes and what the various parts of the
computer do with it.

There are two ways you can program your computer.  You can speak
HEXIDECIMAL code (machine language).  An instruction would look like this: 60.

Your computer takes 60 and converts it into its binary equivalent: 0110
0000.  Notice that this binary translation has eight digits.  These are called
BITS.  Bits are handled by the computer in groups of eight.  One group is
called a BYTE.  A byte is the smallest piece of information a computer can
work with.

In Odyssey2 Hexidecimal language, 60 means "Load a value into Register 0."
(A register is a place where a computer stores information.  There are sixteen
registers in your Odyssey2.  Each register has room for one byte of
information.)

The second computer language your Odyssey2 understands in called ASSEMBLER.
Assembler uses alpha-numeric symbols to input binary code instructions.  An
instruction in Assembler is more phonetic than Hex - but it is also longer.

Example: LDV.0.38 means - Load a value into register 0 - and that value is
38.  (Important: Be sure to enter the periods in the assembler instructions or
the computer will not know what you're talking about.)

In the back of the book, you'll find a complete chart of Instruction Sets
for your Odyssey2.

INSTRUCTION SETS are the codes that tell your computer what you want it to
do with the data you're going to give it.

Also Important: "0" is the equivalent of zero in the numeric section of
your keyboard.  "O" is the letter of the alphabet.

Now, open the gatefold at the back of the book.  You'll find a flow chart
that tells you how to get into the various operating modes of your Odyssey2.
These modes are for displaying data in the registers, entering and executing a
program, rolling through a program to check data and much more.

Leave the front and back gatefolds open.  You'll have your reference
material right in front of you.

We are now ready to re-program the fearsome Creepy Crawler.  First, we'll
enter in Hex - and then we'll do a variation in Assembler.


Creepy Crawler

Press the POWER BUTTON OFF and ON to clear the computer.

Press RESET "Command" appears on your screen.  Your computer is in the COMMAND
mode and ready to accept instructions.  It knows you want it to do something
but doesn't yet know what.

Press P "Program" appears on the screen.  "Aha," thinks the computer.
"Somebody wants to enter a program!  I wonder what language this person will
speak!"

Press M "Hex Input" appears on the screen.  The computer now knows you will be
communicating in HEX.  You're going to be using the Hexidecimal Operational
Code (OP CODE).

Press I Step 00 appears on the screen and the computer is ready and waiting to
accept data.


00

Press 60 This is Op code for Load Register 0.  Register 0 is one of sixteen
registers in your Odyssey2 that make up part of its Random Access Memory
(RAM).  Each register is a small memory devide that provides temporary storage
for data and instructions which will eventually be needed by the ARITHMETIC
LOGIC UNIT (ALU) - the place where all simple reasoning and arithmetic
operations are performed.  Look at the registers in the computer as sixteen in
and out boxes on a desk that is shared by both you and the Arithmetic Logic
Unit.

Press ENTER Program Step 01 appears on the screen.  Register 0 has now been
activated to accept your entry upon execution of the program.  (The program
steps you enter into the computer do not actually become functional until you
press E [EXECUTE] at the completion of the program.)


01

Press 3A You have just selected an electronic figure from your computer's
gallery of electronic art and symbols, which are stored in the symbol/sound
generator.  You'll find the entire gallery in the fold-out at the back of the
book.  We've selected the little man as an example, but you can actually use
any of the figures or symbols for this program.  They have been permanently
stored in your computer.

There are two parts to the memory unit in your computer.  The ROM (Read Only
Memory) contains the instruction sets and constants to be used in programming.
(The constants may be repetitive numbers needed for mathematical computation
by the ALU - Arithmetic Logic Unit, or they may be letters, numbers, or
symbols which you have entered into the Odyssey21 in a program which will
remain the same throughout the program.  See the program "Message.")  The
other part of the computer's memory is called RAM (RANDOM ACCESS MEMORY).
This memory component is like a blackboard.  Programs, instruction sets and
constants can be entered and later erased so that new data can be entered.
You're writing this program on the RAM component of the microprocessor in your
Odyssey2.

Press ENTER Program step 02 appears on the screen.  The little man will be
loaded into Register 0.

02

Press 61  This is Op Code for LOAD REGISTER 1.  It tells your computer you
want to give input to that data storage unit.

Press ENTER  Prgram step 03 appears on the screen - and the door to Register 1
will open to receive data

03

Press 0C  This is Op Code for a blank like the space between words in a
sentance.

Press ENTER  Program step 04 appears on your screen.  The blank will be loaded
in to Register 1.

04

Press 6B  This is Op Code for positioning.  You are opening the door to
Register B and telling it you want it to display the little man at a certain
place on the screen upon execution of the program.  You'll let it know where.

Press ENTER  Program step 05 appears.  The door to Register B will open.

05

Press 00  This entry tells the computer you will want it to display the little
man at the furthest left position on the screen.

Press ENTER  Program step 06 appears on your screen.  The positioning
information will be loaded into Register B.

Register B is the register that positions symbols or characters on the screen.
It has been given eleven positions.  00 is the furthest left.  0A is the
furthest right.  When Register B outputs on the screen, it automatically
increments or advances by one.  If we output a symbol in 00 (position one),
the symbol will appear in the first position and Register B will then advance
automatically to position 2 (01).  If Register B outputs in the last position
(0A), it automatically resets itself back to the first position (00) on the
next step.  Whatever data was in that first position will be replaced by the
new input.

06

Press C0  This is the Op Code that tells the computer you are going to want to
bring that little man to the screen.  You have given him a way to get out of
Register B.

Press ENTER  Program Step 07 appears on the screen.

07

Press C1  This is Op Code for telling the computer you want to bring that
blank in Register 1 to the screen.

Press ENTER  Program step 08 appears on your screen to tell you everything is
going along smoothly.

08

Press 05  It's sound effects time.  This is an Op Code that tells the computer
you will want to hear a one second buzz.

Press ENTER  Program step 09 appears.

09

Press 08  This Op Code tells the computer you want it to come with an
unlimited sequence of random numbers.  The computers that encipher and
decipher secret messages for governments do this everyday.  In the old days,
crypt keys remained constant and could be broken easily.  Today, they change
constantly and at random.  Today, it takes one computer to break another's
cipher.

Press ENTER  The random number instructions are entered into your computer.
Program step 10 appears on the screen.

10

Press BB  This is Op Code for UNPACK Register B.  This is the Register we use
to position our little man on the screen.  This unpacking instruction takes
the random two digit number selected by the Accumulator and places one digit
in Register B (we are unpacking Register B, thus the Op Code BB) and the other
digit in the Register immediately following B, which is Register C.  The digit
in Register C is ignored.  Another example of unpacking - If we had unpacked
Register 0, the Op Code would have been B0, and one digit on the random number
would have been placed in Register 0 and the second digit in Register 1.

To look at it another way, think of the Accumulator as a suitcase and the
registers as a tall dresser with 16 drawers.  You unpack two items from your
suitcase and put the first away in a drawer.  The second item will
automatically go to the drawer just below it.

At the end of the Creepy Crawler program, a variation is written explaining
how to use the second digit of the random number which was loaded into
Register C, along with numerous figures to execute a random display of figures
on the screen.

Through this unpacking instruction, the positioning Register (Register B) is
loaded from the Accumulator with a random number.  It is this instruction
which will cause our little man to travel to unpredictable places on the
screen.  (The Accumulator is a small memory device in the CPU that provides
temporary storage for the Arithmetic Logic Unit.  It can store the result of
an ALU operation or serve as an operation source [OPERAND] for the ALU.)

Press ENTER  The unpacking instruction is entered and programm step 11 appears
on your screen.

11

Press 12  This OP Code tells your computer you're going to want it to return
to a previously programmed step.

Press ENTER  Program step 12 appears on the screen and the computer wonders
which program steps you wish repeated.

12

Press 06  You have just told the computer you want it ot go through the
motions and always return to program step 06.  This was the place you wanted
the little man positioned on the screen which was subsequently combined with a
random number to change the positioning on the screen.  In effect, you have
now "looped" part of your program.  It will do its thing endlessly with
endless variations.

Press ENTER  The computer salutes and will do as you ordered.  Program step 13
appears.

Press RESET  The program is stored and you are back in the COMMAND mode.
"Command" appears on your screen.

Press E  You have instructed the computer to execute your instructions.  The
fearsone Creepy Crawler appears on your screen.  The little man or whatever
symbol you have chosen will flash and buzz in different positions on the
screen.

Forever.
Or, until you turn it off.
Or, change the program.
Whichever comes first.

Important!  The power switch on your console is your program eraser.  Turn it
off and the program is cleared from the unit automatically.  Turn it on -
and you're ready to enter a new program.

Now that you've entered Creepy Crawler in HEX, Try entering this variation in
ASSEMBLER language.  We will call this program Creepy Crawler with an All-Star
Cast of Thousands.

First, turn the power off and on to erase any previous programming.  Now,
check the fold-out Operational Flow Chart to see how to get into the Assembler
Input Mode.

Press RESET
Press P
Press A
Press I

You are now in the Assembler Mode at program step 00 and ready to go.  One
thing.  Be sure to enter the periods as well as the letters and numbers.

Press L
Press D
Press V
Press .
Press 2
Press .
Press 1
Press 3
Press enter

We are now at Program step 02.  Continue entering in Assembler until you get
to Program step 13.  At this step you will begin entering a variety of symbols
in HEX.  There is no Assembler equivalent for them - so after Program step 12,
switch over to the HEX Input Mode.  Check the Operational Flow Chart and then
-
Press CLEAR
Press ROLL
Press CLEAR
Press M
Press I

After you finish entering the program, press RESET to store the program - then
press E (EXECUTE) and watch what happens!

Creepy Crawler Version II

     Hex    Assembler
Step Code   Code       Byte   Remarks
------------------------------------------------------------------------
00   62 13  LDV.2.13    2     Load Reg. 2 with 13
02   08     RND         1     Accum. selects a random number
03   BB     UNP.B       1     Unpack the random number into Reg. B and C
04   9C     LDA.C       1     Load the Accum. from Reg. C
05   E2     ADD.2       1     Add the contents of Reg. 2 to the Accum.
06   AC     STO.C       1     Store the contents of the Accum. in Reg. C
07   09     MOV         1     Load Accum. from a Program step
08   0B     OTA         1     Output from Accum. to screen
09   05     SIG         1     One second buzz
10   00     NOP         1     No operation (used as pause)
11   12 02  GTO.02      2     Instructs Odyssey2 to go to Program step
                              02 and repeat program
13   32                 1     Must enter Hex Mode (see page 27)
14   33                 1
15   3A                 1
16   34                 1
17   35                 1     Hex codes for various symbols.  These
18   37                 1     symbols with their Hex Code equivalents
19   3D                 1     are shown at the front of the book.
20   3E                 1
21   36                 1
22   3C                 1



The Roll Mode - Your Program Trouble Shooter

The Roll Mode is for checking a program step to be sure it contains the
correct data.  It is also for making a change in a program step without having
to erase and re-enter an entire program.

To enter the Roll Mode, press R if you are in either the Assember or HEX
input modes.  If you are in the EXECUTION mode, press RESET, the P, the M
(HEX) or A (ASSEMBLER) - and then press R.

Then, press U to display the program steps upward (00-99) - or press D to
display the program steps downward (99-00).  The Roll Mode will always display
its information in HEX - even if you have been entering in Assembler.

If everything checks out, roll to the last program step entered and press
CLEAR to re-enter the Assembler or HEX input mode.

If you wish to make a change, press CLEAR at the program step you wish to
change.  The data will be cleared.

Enter M for HEX or A for Assembler, depending on the code you have been
using.

Press I - the program step number you wish to change will appear on the
screen.

Enter the new data.

Press RESET  You will be back in the COMMAND Mode and are ready to go on
with the program.

The following series of programs will be presented with a running
commentary that will tell you exactly where the data is going and what is
happening to it.  These programs are written in HEX code.  At the end of each
program, you'll find a summary written in HEX as well as Assembler, so you can
enter each program in either language.

Addition - Program A

This program will add two one digit numbers and display the total.  Press the
POWER BUTTON off and on to clear the computer.

Press RESET  "Command" appears on your screen.  Your computer is ready to
accept instruction.

Press P  "Program"  appears on the screen.

Press M  "Hex Input" appears on the screen.  You have told the computer you
will be using the Hexidecimal Operational Code (Op Code).

Press I  Step 00 appears on the screen.  The computer is ready to accept data.

00

Press 70  Press ENTER  You have told the computer you are going to input the
first number into Register 0.

01

Press 04  Press ENTER  You instruct the computer to feed the second number of
the addition problems in to the Accumulator.  Remember, the Accumulator
provides temporary storage for the ALU where the numbers are going to be
crunched.

02

Press E0  Press ENTER  This instructs the computer to add the contents of
Register 0 to the contents of the Accumulator and to store the sum in the
Accumulator.

03

Press B1  Press ENTER  This Op Code is an unpacking instruction.  It tells the
computer to unpack the sum which has been stored in the Accumulator into
Register 1 and Register 2.

04

Press 6B  Press ENTER  This starts a positioning instruction.

05

Press 00  Press ENTER  This Op Code tells the computer to display subsequent
information at the 00 position on your TV screen.

06

Press C1  Press ENTER  You tell the computer you will want to output the
information in Register 1 (first digit sum).

07

Press C2  Press ENTER  You also want to output the data in Register 2 (Second
digit sum).

08

Press 12  Press ENTER  This tells the computer you want it always to return to
a certain step and repeat the program from that point.

09

Press 00  Press ENTER  00 is the step you want the computer to return to and
repeat.  Now, the computer will perform a continuous series of addition
problems.

The program is now completed.

Press RESET  The program is now stored in the computer's memory and you are
back in the COMMAND Mode.

Press E  The computer executes your program.  A question mark appears on the
screen.  The computer is asking for two 1 digit numbers to add.

Enter the First Number.  Press any digit from 0 through 9.  You will hear a
beep confirming entry.  The number will not appear on the screen.  That
instruction was not included in this program.

Enter the Second Number.  Press any digit 0 through 9 and the sum total of the
two entered numbers will immediately appear on the screen.

To enter a new problem, press any single digit number.  Then, press the other
single digit number.

The previous sum will be replaced by the answer of the new addition problem as
soon as you have entered the second number of the new problem.

Now, here is the addition problem you have just entered expressed in both HEX
and ASSEMBLER codes.  Note the following points.

Important: Remember to get into the proper input mode for the language you are
using.
Press PMI for HEX.
Press PAI for Assembler.

Very Important: Look at Program step 04.  It is a two Byte instruction.
Remember, in Binary each byte is composed of eight bits.
6B (HEX = 0110 1011 (BINARY).  00 (HEX) = 0000 0000 (BINARY).  Therefore,
6B 00 is a two byte instruction.  If you are in the HEX mode, each Byte must
be entered separately.

Press 6B
Press ENTER
Press 00
Press ENTER

If you are in the Assembler mode, both Bytes are fed into the computer with
one entry.

Press L
Press D
Press V
Press .
Press B
Press .
Press 0
Press 0
Press ENTER

In either language, you will see Program step 06 on the screen after the data
is entered.  Now, push the Power Button to erase any previous data...choose
one of the input codes...and enter the program.  Be sure to press ENTER after
each step.


Addition - Program A

     Hex    Assembler
Step Code   Code       Byte   Remarks
------------------------------------------------------------------
00   70     INP.0       1     Input Reg. 0 with 1st number
01   04     INA         1     Input Accum. with 2nd number
02   E0     ADD.0       1     Add Reg. 0 to Accum.
03   B1     UNP.1       1     Unpack Accum. into REg. 1 and Reg. 2
04   6B 00  LDV.B.00    2     Set output position to 00
06   C1     OUT.1       1     Output Reg. 1, 1st digit sum
07   C2     OUT.2       1     Output Reg. 2, 2nd digit sum
08   12 00  GTO.00      2     Go to step 00 and repeat


Addition - Program B

This program will also add two one digit number.  However, this time when you
enter the second number, the entire problem will appear on the screen.
(Example: 2+4=6).  You will be entering + and = signes in this program.

First, press the POWER BUTTON off and on to clear the computer.  Then -

Press RESET  "Command" will appear on your screen, and your computer is all
ears.

Press P  "Program" appears on your screen.

Press M  "Hex Input" appears on your screen.  The computer knows you will be
using Op COde (Hexidecimal Operation Code).

Press I  Step 00 appears on the screen.  You are ready to input data.

00

Press 70  Press ENTER  You tell the computer the first number will be entered
into Register 0.  01 appears on your screen.

01

Press 04  Press ENTER  You tell the computer to accept the second number into
the Accumulator.  02 appears on the screen.

02

Press 6B  Press ENTER  This starts an output position entry.

03

Press 00  Press ENTER  The output position is set at 00 at the far left of the
screen.

04

Press C0  Press ENTER  The output channel from Register 0 will open for the
first number of the addition problem.

05

Press 63  Press ENTER  The input channel to Register 3 will open.

06

Press 10  Press ENTER  10 will be loaded into Register 3. 10 is Op Code for
the (+) sign.

07

Press C3  Press ENTER  The output channel from Register 3 will open so the (+)
sign can be displayed on the screen.

08

Press 0B  Press ENTER  The output channel of the Accumulator will open so that
the second number can be displayed on the screen.

09

Press 63  Press ENTER  The input channel to Register 3 will open.

10

Press 2B  Press ENTER  2B will be loaded into Register 3.  2B is Op Code for
the (=) sign.

11

Press C3  Press ENTER  The output channel from Register 3 is opened so the (=)
sign may be displayed on the screen.

12

Press E0  Press ENTER  This instruction adds the contents of Register 0 to the
contents of the Accumulator and stores the result in the Accumulator.
Remember, Register 0 contained the first number of the addition problem.  The
Accumulator held the second number.

13

Press B1  Press ENTER  This program step unpacks the contents of the
Accumulator storing the first digit of the sum in Register 1 and the second
digit of the sum in Register 2.

14

Press C1  Press ENTER  The output channel from Register 1 will open to let the
first digit sum be displayed on the screen.

15

Press C2  Press ENTER  The output channel from Register 2 will open to let the
second digit sum be displayed on the screen.

16

Press 12  Press ENTER  This begins an instruction to return to a previous
step.

17

Press 00  Press ENTER  The computer is instructed to return to step 00 and be
ready to solve a new addition problem.  The old problemm will not erase from
the screen until both digits of the new problem are entered.

Press RESET  The program is now stored in the computer.

Press E  The computer is ready to execute the program.  A question mark
appears on the screen asking for input.

Press any single digit number.  Nothing appears on the screen.

Press a second single digit number.  The entire problem and the solution
appear on the screen.  Both will remain there until two new digits are
entered.

Addition - Program B

     Hex    Assembler
Step Code   Code       Byte   Remarks
------------------------------------------------------------------
00   70     INP.0       1     Input Reg. 0 with 1st number
01   04     INA         1     Input Accum. with 2nd number
02   6B 00  LDV.B.00    2     Set output position
04   C0     OUT.0       1     Output 1st number from Reg. 0
05   63 10  LDV.3.10    2     Load Reg. 3 with (+) sign
07   C3     OUT.3       1     Out Reg. 3, (/) + on screen
08   0B     OTA         1     Output 2nd number
09   63 2B  LDV.3.2B    2     Load Reg. 3 with (=) sign
11   C3     OUT.3       1     Output Reg. 3, (/) = on screen
12   E0     ADD.0       1     Add Reg. 0 to Accum.
13   B1     UNP.1       1     Unpack Accum. into Reg. 1 and Reg. 2
14   C1     OUT.1       1     Output Reg. 1, 1st digit sum
15   C2     OUT.2       1     Output Reg. 2, 2nd digit sum
16   12 00  GTO.00      2     Go to step 00 and repeat


Addition - Program C

After you enter this program a question mark on the screen asks you to press
in two one digit numbers for the computer to add.  The first number appears on
the screen followed by (+) sign.  When you press the second number, it appears
on the screen followed by a (=) sign and the answer.  When the first digit of
the next addition problem is entered, the first problem will disappear from
the screen.  To begin, turn off the power to erase the previous program.

Press RESET  You[sic] computer is in the "Command" Mode and ready to accept
instructions.

Press P  The computer enters the "Program" Mode.

Press M  "Hex Input" appears on the screen.  The computer is ready to accept
instructions in Op Code.

Press I  Step 00 appears on the screen and the computer is ready for the
program.

00

Press 6B  Press ENTER  You are setting the output position of Register B.

01

Press 00  Press ENTER  That output position is 00 at the far left of the
screen.

02

Press 70  Press ENTER  You tell the computer that the first number of the
addition problem will be stored in Register 0.

03

Press C0  Press ENTER  This tells the computer you will want it to output the
contents of Register 0.

04

Press 63  Press ENTER  You are preparing Register 3 to accept data.

05

Press 10  Press ENTER  Register 3 will be loaded with a 10 - the code for a
(+) sign.  You will find the complete code for all of the graphics stored in
your computer on the fold-out at the back of the book.

06

Press C3  Press ENTER  This will open the way to output the (+) sign from
Register 3.

07

Press 04  Press ENTER  This will open the Accumulator for future input.

08

Press 0B  Press ENTER  The output channel of the Accumulator is set to open.

09

Press 63  Press ENTER  You want to laod a value into Register 3.

10

Press 2B  Press ENTER  That value is 2B - the code for the (=) sign.

11

Press C3  Press ENTER  This will open the way to output the (=) sign from
Register 3.

12

Press E0  Press ENTER  The computer will then add the contents of Register 0
to the Accumulator.  Register 0 has already been instructed to accept the
first number in the addition problem (Step 02) - and the Accumulator has been
instructetd to accept the second number.

13

Press B1  Press ENTER  This Op Code will unpack the contents of the
Accumulator (which contains the sum) into Register 1 and Register 2.

14

Press C1  Press ENTER  This will open the output channel of Register 1.

15

Press C2  Press ENTER  This will open the output channel of Register 2.

16

Press 70  Press ENTER  This input is a pause operation.  It tells the computer
to leave the first problem on the screen until another problem is entered.

17

Press 6C  Press ENTER  Register C will be opened for loading.

18

Press 0B  Press ENTER  Register C will be loaded with 0B - the Op Code for the
decimal number 11, which is exactly the number of positions available on the
screen.

19

Press 67  Press ENTER  Register 7 will be ready for loading.

20

Press 0C  Press ENTER  0C is Op Code for blank spaces as indicated in the
computer graphics section in the fold-out at the back of the book.  Register 7
will be loaded with blank spaces.  The computer will use these blank spaces to
erase the old problem on the screen when the first digit of the new problem is
entered.

21

Press 9C  Press ENTER  The Accumulator will be loaded with the contents of
Register C - the decimal number 11.

22

Press 64  Press ENTER  This will open Register 4 to accept data.

23

Press 00  Press ENTER  Register 4 will be loaded with 00.

24

Press 02  Press ENTER  The amount in the Accumulator (11 - the number of
positions on the screen) will be decremented (subtracted) by one each time
this step is reached.

25

Press C7  Press ENTER  Register 1 will output its blank spaces.

26

Press 24  Press ENTER  This is a branch instruction - sort of a fork in the
electronic road.  The computer is instructed to continue on to the next
program step if the number in the Accumulator equals the number in Register 4
(00).

27

Press 24  Press ENTER  The computer is instructted to return to step 24 if
the number in Register 4 is not equal to the Accumulator.  Step 24 will
decrement the contents of the Accumulator (which originally was 11) by 1 each
time until the Accumulator is reset at 00 to match Register 4.  Program steps
16 through 27 demonstrate how a computer erases by outputting blank spaces to
the screen.

28

Press 6B  Press ENTER  We are resetting Register B to return to its original
output position once the Accumulator is equal to Register 4.

29

Press 00  Press ENTER  The output position of Register B is set at the extreme
left position of the screen.

30

Press 12  Press ENTER  This Op Code instructs the computer to branch to
another program step when the amount in the Accumulator equals 00.

31

Press 03  Press ENTER  The step the cocmputer returns to is 03.  Now, you are
able to enter and solve repeated addition problems.

Press RESET  The program is stored.

Press E  The program is executed.  See the beginning of the program for use
instructions.

Addition - Program C

     Hex    Assembler
Step Code   Code       Byte   Remarks
----------------------------------------------------------------
00   6B 00  LDV.B.00    2     Set output position to 00
02   70     INP.0       1     Input 1st number to Reg. 0
03   C0     OUT.0       1     Output Reg. 0
04   63 10  LDV.3.10    2     Load Reg. with (+) sign
06   C3     OUT.3       1     Output (+) sign from Reg. 3
07   04     INA         1     Input to Accum. (second number)
08   0B     OTA         1     Output from Accum.
09   63 2B  LDV.3.2B    2     Load Reg. 3 with (=) sign
11   C3     OUT.3       1     Output (=) sign from Reg. 3
12   E0     ADD.0       1     Add Reg. 0 to Accum.
13   B1     UNP.1       1     Unpack Accum. to Reg. 1 and Reg. 2
14   C1     OUT.1       1     Output Reg. 1
15   C2     OUT.2       1     Output Reg. 2
16   70     INP.0       1     This is used as a pause operation
17   6C 0B  LDV.C.0B    2     Load Reg. C with Hex 0B (#11)
19   6C 0C  LDV.7.0C    2     Load Reg. 7 with blank spaces
21   9C     LDA.C       1     Load Accum. from Reg. C
22   64 00  LDV.4.00    2     Load Reg. 4 with 00
24   02     DEC         1     Subtract 1 from Accum.
25   C7     OUT.7       1     Output Reg. 7 (blank spaces)
26   24 24  BNE.4.24    2     Branch if Accum. does not = Reg. 4
28   6B 00  LDV.B.00    2     Set output position to 00
30   12 03  GTO.03      2     Go to step 03 and repeat


One Digit Multiplication

After you enter this program, a question mark will appear on the screen asking
for input.  The first digit entered is the number you wish to multiply (the
nultiplicand).  It appears on the screen with an (X) sign.  The second digit
entered is the multiplier.  The complete problem will now appear on the screen
along with the answer.  Odyssey2 solves multiplication through an addition
process.  If the problem is 3 X 7, the computer will arrive at the answer by
adding 7+7+7.  Program steps 00 through 11 are instructions which allow the
problem to be displayed on the screen.  The mathematical operational sequence
begins with step 12.

First, press the POWER BUTTON off and on to erase the previous program.

Press RESET  You are in the "Command" Mode.

Press P  You enter the "Program" Mode.

Press M "Hex Input" appears on the screen.  The computer is ready for Op Code
instructions.

Press I  Step 00 appears on the screen and the computer is ready for the
program.

00

Press 6B  Press ENTER  The output position of Register B is ready for setting.

01

Press 00  Press ENTER  You set the output of Register B for the far left of
the screen.

02

Press 70  Press ENTER  The multiplicand is directed to be stored in Register
0.

03

Press C0  Press ENTER  Register 0 is given an output channel.

04

Press 66  Press ENTER  The door will be opened to Register 6.

05

Press 29  Press ENTER  An (X) sign will be entered into Register 6.

06

Press C6  Press ENTER  Register 6 is given an output channel.

07

Press 71  Press ENTER  The multiplier will be stored into Register 1.

08

Press C1  Press ENTER  The multiplier is given a way out of Register 1.

09

Press 67  Press ENTER  The door to Register 7 is instructed to open.

10

Press 2B  Press ENTER  2B is Op Code for (=).  The (=) sign will be loaded
into Register 7.

11

Press C7  Press ENTER  This will provide an output channel for Register 7.

12

Press 90  Press ENTER  The Accumulator is instructed to be ready to accept data
from Register 0.  This is the Register that holds the number you want to
multiply.  The Accumulator will be loaded with the same value as the contents
of Register 0 - however, Register 0 will continue to retain its data.

13

Press E0  Press ENTER  The computer is instructed to add the contents of the
Accumulator to Register 0.  Remember, that Odyssey2 multiplies by a series of
addition steps.  This is the first addition step.

14

Press A2  Press ENTER  The sum of the digits from the Accumulator and Register
0 will be stored in Register 2.

15

Press 91  Press ENTER  The Accumulator will be loaded from Register 1 which
holds the multiplier.  The Accumulator will now know the number of addition
steps it must perform to arrive at an answer.

16

Press 02  Press ENTER  This step will decrement the Accumulator which contains
the multiplier by 1 so that the computer can keep track of how many addition
steps have been made.

17

Press A1  Press ENTER  The difference will be stored in Register 1.

18

Press 63  Press ENTER  The door to Register 3 will open.

19

Press 01  Press ENTER  01 will be stored in Register 3.  This will give the
computer a reference point which will halt the addition process.  When the
Accumulator contains the contents of Register 1 (the multiplier), it is
compared to the contents of Register 3 (which is 01).  If the contents in
Register 1, which is now in the Accumulator, and Register 3 coincide, the
computer will stop adding.  If they are not equal, the computer will loop back
and continue the addition process.

20

Press 33  Press ENTER  This starts a branch operation.

21

Press 25  Press ENTER  The computer is instructed to branch to step 25 if the
contents of the Accumulator and Register 3 are equal.  In which case, the
answer will be unpacked and displayed on the screen.

22

Press 92  Press ENTER  The Accumulator will be loaded with the information in
Register 2, which contains the data fed in Program Step 14.

23

Press 12  Press ENTER  The computer is instructed to return to a previous step
in the program if the conditions in program step 19 have not been met.

24

Press 13  Press ENTER  The computer is instructed to return to step 13 and
once aggain add the contents of Register 0 to the Accumulator.  (Register 0
holds the multiplicand.)

25

Press 92  Press ENTER  The Accumulator will be loaded with the contents of
Register 2 which contains the sum of the addition operations.  We are almost
at the end of the tunnel.  This operation is performed when the contents of
the Accumulator and Register 3 are equal.

26

Press B4  Press ENTER  This is a two digit unpacking operation, which has been
explained in Addition Program A.

27

Press C4  Press ENTER  An output channel for Register 4.

28

Press C5  Press ENTER  An output channel for Register 5.

29

Press 12  Press ENTER  You instruct the computer to return to a previous
program step.

30

Press 00  Press ENTER  That step is 00.  The computer will now be ready to
accept a new multiplication problem.

Press RESET  The program is stored.

Press E  The program is executed.


One Digit Multiplication


     Hex    Assembler
Step Code   Code       Byte   Remarks
--------------------------------------------------------------
00   6B 00  LDV.B.00    2     Set output position
02   70     INP.0       1     Multiplicand stored in Reg. 0
03   C0     OUT.0       1     Output multiplicand
04   66 29  LDV.6.29    2     Symbol (X) stored in Reg. 6
06   C6     OUT.6       1     Output Reg. 6; Reg.6=(X)
07   71     INP.1       1     Multiplier stored in Reg. 1
08   C1     OUT.1       1     Output Multiplier
09   67 2B  LDV.7.2B    2     Symbol (=) stored in Reg. 7
11   C7     OUT.7       1     Output Reg. 7
12   90     LDA.0       1     Load Accum. from Reg. 0
13   E0     ADD.0       1     Add Accum. to Reg. 0
14   A2     STO.2       1     Store sum in Reg. 2
15   91     LDA.1       1     Load Accum. from Reg. 1
16   02     DEC         1     Decrement Accum. by 1
17   A1     STO.1       1     Store difference in Reg. 1
18   63 01  LDV.3.01    2     Load Reg. 3 with 01
20   33 25  BEQ.3.25    2     Go to step 25 if Accum. = Reg. 3
22   92     LDA.2       1     Load Accum. from Reg. 2
23   12 13  GTO.13      2     Go to step 13
25   92     LDA.2       1     Load Accum. from Reg. 2
26   B4     UNP.4       1     Unpack two digits
27   C4     OUT.4       1     Output Reg. 4
28   C5     OUT.5       1     Output Reg. 5
29   12 00  GTO.00      2     Go to step 00 and repeat


One Digit Division


A question mark will appear on the screen.  The first number entered will be
the dividend and it will be followed by a (./.) sign.  The second number
entered will be the divisor.  It will appear on the screen along with an (=)
sign and the answer.  Your Odyssey2 computer accomplishes division by a series
of subtractions.  It's the Odyssey2 multiplication process in reverse.

Note: There are two conditions in division that must be provided.  The first
condition is when the divisor can be divided into the dividend equally.
Example: 6/2 = 3.  The second condition is when the divisor cannot be divided
into the dividend equally and there is a remainder.  Example: 9/2=4+R.  Your
Odyssey2 has been instructed to display (+R) if there is a remainder.  This
program provides branching instructions to satisfy both conditions.

To begin, turn the POWER BUTTON off and on to erase any previous program.

Press RESET  You are in the "Command" mode.

Press P  You have entered the "Program" mode.

Press M  "Hex Input" appears on the screen.  The computer is ready to accept
instructions in Op Code.

Press I  Step 00 appears on the screen, and you are ready to enter the
program.


00

Press 63  Press ENTER  The door to Register 3 will be opened.

01

Press 00  Press ENTER  We call this "initialization" - a step to insure that
Register 3 is set at absolute zero value after each problem is solved.
Register 3 will contain the sum of the subtraction operations Odyssey2 will
perform to find the quotient.

02

Press 6B  Press ENTER  The door to Register B will be opened.

03

Press 00  Press ENTER  Register B will be positioned to output at the far left
of the screen.

04

Press 70  Press ENTER  The number to be divided (the dividend) will go into
Register 0 the dividend must always be larger than the divisor.

05

Press C0  Press ENTER  The output channel to Register 0 is set to open.

06

Press 69  Press ENTER  Register 9 will be opened for input.

07

Press 2A  Press ENTER  2A is Op Code for (./.).  The division sign will go
into Register 9.

08

Press C9  Press ENTER  The output channel of Register 9 is set to open.

09

Press 71  Press ENTER  The divisor will be loaded into Register 1.

10

Press C1  Press ENTER  The output channel of Register 1 is instructed to open.

11

Press 6A  Press ENTER  The door to Register A will be opened.

12

Press 2B  Press ENTER  2B is Op Code for (=).  The equal sign will go into
Register A.

13

Press CA  Press ENTER  The Register A output channel is instructed to open.

14

Press 91  Press ENTER  The Accumulator will be loaded with the contents of
Register 1 which contains the divisor.  We are going to use a sample problem
so the explanation will be easier (6/2=3).  The Accumulator will be loaded
with the divisor (2).

15

Press D0  Press ENTER  The contents of the Accumulator will be subtracted from
the contents of Register 0 which contains the dividend (6).

16

Press A0  Press ENTER  The difference (4) between the dividend and the divisor
(6-2=4) will be stored in Register 0.

17

Press 93  Press ENTER  The Accumulator will be loaded with the contents of
Register 3.  This is the Register that was "initialized" at 00 so that we
could keep track of the number of times we subtracted.

18

Press 03  Press ENTER  A 1 will then be added to the Accumulator.  This is
called an increment.

19

Press A3  Press ENTER  The sum of the Accumulator is then stored in Register
3.  This Register now contains 01.

20

Press 90  Press ENTER  The Accumulator will be loaded with the contents of
Register 0.  Register 0 has been loaded with a value of 4, the difference
between the dividend and the divisor.  The value was loaded into Register 0 in
Program step 16.

21

Press 13  Press ENTER  This will be the start of a branch operation.

22

Press 40  Press ENTER  The computer wil branch to step 40 if the Accumulator
equals 0.  Once the Accumulator equals 0, the problem is finished and Program
step 40 will unpack the answer and it will be displayed on the screen.

23

Press 91  Press ENTER  If the Accumulator does not equal 0, it will go to this
program step.  The Accumulator will be loaded with the contents of Register 1
which contains the divisor (2).

24

Press 50  Press ENTER  Another branch operation will be started.

25

Press 28  Press ENTER  The computer will be instructed to branch to program
step 28 if Register 0 which contains the dividend (4) is less than the
Accumulator which contains the divisor (2) from Register 1.

26

Press 12  Press ENTER  This tells the computer to return to a previous step if
Register 0 is not less than the Accumulator.

27

Press 15  Press ENTER  This completes the return instructions.  The computer
is programmed to return to step 15.  This step begins the subtraction
operations which will continue until Register 0 is loaded into the Accumulator
at step 21 and, the Accumulator equals 0 in this example.  When this condition
is met, Odyssey2 will loop to Program step 40.

28

Press 93  Press ENTER  This is the step your computer will branch to if a
remainder is included.  The branching instructions were given in steps 24 and
25.  They programmed the computer to branch to step 28 if Register 0 which
contains the dividend is less than the Accumulator which at this point,
contains the divisor.  We will use 9/2=4+R as our sample problem.  All
programsteps have been the same up to this point.  The computer has looped to
step 15 several times.  Register 0 now contains 01 and the Accumulator
contains 02.  This step will load the Accumulator from Register 3 which
contains the number of times (2) has been subtracted from (9) which is (4).

29

Press B4  Press ENTER  This instruction will unpack the answer.

30

Press C4  Press ENTER  The first digit, stored in Register 4, will be
displayed on the screen.

31

Press C5  Press ENTER  The second digit, stored in Register 5, will be
displayed on the screen.

32

Press 66  Press ENTER  Register 6 will open.

33

Press 10  Press ENTER  10 will be loaded into Register 6.  10 is the Op Code
for (./.).

34

Press 67  Press ENTER  Register 7 will be opened.

35

Press 13  Press ENTER  13 will be loaded into Register 7.  13 is the Op Code
for (R).

36

Press C6  Press ENTER  The output channel for the (./.) sign will be opened.

37

Press C7  Press ENTER  The output channel for (R) will open.

38

Press 12  Press ENTER  The computer is instructed to return to a previous
step.

39

Press 00  Press ENTER  The computer will return to step 00 and be ready to
solve a new problem.  Our program ends at this point if we have solved a
problem that contains a remainder.  If not, as in our first example (6/2=3),
we would have jumped from Program step 21 to Program step 40.

40

Press 93  Press ENTER  The Accumulator will be loaded with the contents of
Register 3.  It will contain the number of times the divisor has been
subtracted from the dividend.  In step 21 the computer was programmed to
branch to this step when the contents of the Accumulator equaled 0.  We were
using 6/2 as our example so at this point Register 3 contains (3) ---the
number of times (2) has been subtracted from (6).

41

Press B4  Press ENTER  This unpacking operation will convert the answer from
binary into decimal.

42

Press C4  Press ENTER  The output channel of Register 4 will be opened for the
first digit.

43

Press C5  Press ENTER  The output channel of Register 5 will be opened for the
second digit.

44

Press 66  Press ENTER  Register 6 will open.

45

Press 0C  Press ENTER  Register 6 will be loaded with 0C which is Op Code for
a blank space.

46

Press 67  Press ENTER  Register 7 will open.

47

Press 0C  Press ENTER  Register 7 will be loaded with a blank space.
Registers 6 and 7 have been loaded with blanks so that (+R) will not be
displayed on the screen when this branch of the program is employed by the
computer.

48

Press C6  Press ENTER  The output channel from Register 6 will open.

49

Press C7  Press ENTER  The output channel from Register 7 will open.

50

Press 12  Press ENTER  The computer is instructed to return to a previous
step.

51

Press 00  Press ENTER  The computer is instructed to return to step 00 and be
ready to solve another problem.

Press RESET  The program is stored.

Press E  The program is executed.


One Digit Division


     Hex    Assembler
Step Code   Code       Byte   Remarks
-----------------------------------------------------------------------------
00   63 00  LDV.3.00    2     Reg. 3 = 00 (initialization)
02   6B 00  LDV.B.00    2     Reg. B = 00 (positioning)
04   70     INP.0       1     Dividend stored in Reg. 0
05   C0     OUT.0       1     Output Reg. 0
06   69 2A  LDV.9.2A    2     Symbol (./.) stored in Reg. 9
08   C9     OUT.9       1     Output Reg. 9
09   71     INP.1       1     Divisor stored in Reg. 1
10   C1     OUT.1       1     Output Reg. 1
11   6A 2B  LDV.A.2B    2     Symbol (=) stored in Reg. A
13   CA     OUT.A       1     Output Reg. A
14   91     LDA.1       1     Load Accum. from Reg. 1
15   D0     SUB.0       1     Sub Accum. from Reg. 0
16   A0     STO.0       1     Store difference in Reg. 0
17   93     LDA.3       1     Load Accum. from Reg. 3
18   03     INC         1     Add 1 to the Accum.
19   A3     STO.3       1     Store sum in Reg. 3
20   90     LDA.0       1     Load Accum. from Reg. 0
21   13 40  BRZ.40      2     Branch to step 40 if Accum. equals 0
23   91     LDA.1       1     Load Accum. from Reg. 1
24   50 28  BLS.0.28    2     Branch to step 28 if Reg. 0 is less than Accum.
26   12 15  GTO.15      2     Go to step 15
28   93     LDA.3       1     Load Accum. from Reg. 3
29   B4     UNP.4       1     Unpack two digits
30   C4     OUT.4       1     Output 1st digit which is stored in Reg. 4
31   C5     OUT.5       1     Output 2nd digit which is stored in Reg. 5
32   66 10  LDV.6.10    2     Symbol (+) stored in Reg. 6
34   67 13  LDV.7.13    2     Symbol (R) stored in Reg. 7
36   C6     OUT.6       1     Output (+) sign
37   C7     OUT.7       1     Output (R)
38   12 00  GTO.00      2     Go to step 00
40   93     LDA.3       1     Load Accum. from Reg. 3
41   B4     UNP.4       1     Unpack two digits
42   C4     OUT.4       1     Output 1st digit from Reg. 4
43   C5     OUT.5       1     Output 2nd digit from Reg. 5
44   66 0C  LDV.6.0C    2     A blank is stored in Reg. 6
46   67 0C  LDV.7.0C    2     A blank is stored in Reg. 7
48   C6     OUT.6       1     Output blank
49   C7     OUT.7       1     Output blank
50   12 00  GTO.00      2     Branch to step 00


Area Problems Using "Go to Subroutine" and "Return"

This program gives you an example of how and when to use the instructions "Go
to Subroutine" and "Return".

A "Go to Subroutine" instruction tells the computer to branch to a specific
program step which contains an operation you may wish to use several times in
one program.  You can use the same operation several times without having to
rewrite it.  When writing a prgram using this instruction, the next program
step after the "Go to Subroutine" instruction must be reserved for returning
from the Subroutine.

A program having a "Go to Subroutine" instruction must have a "Return from
Subroutine" instruction as well.

After you enter this program, you will be able to find the area of a rectangle
or the area of a triange.  First, enter the base measurement - then, enter the
height measurement.  Press 1 to find the area of a rectangle.  (Base * Height
= Area).  Press 2 to find the area of a triangle.  (Base * Height / 2 = Area).

Before entering this program, refer to the program on pages 69 and 70 while we
explain how it works.

Program steps 00 through 08 will be the same for both problems.

(00 through 08) Step 08 programs your selection of 1) rectangle area problem,
or 2) triangle area problem to be loaded into the Accumulator.  First, we'll
see what happens when 1 is loaded into the Accumulator.

(09 and 10) Steps 09 and 10 instruct the computer to branch to Program step 13
if the Accumulator (which contains 01) equals the contents of Register 1
(which is 01).  If we had entered a 2, the computer would have proceeded from
Program step 08 to Program steps 11 and 12.

(13 and 14) Program steps 13 and 14 instruct the computer to go to step 66
which starts the multiplication subroutine.  (Base * Height = Area of
Rectangle)

(66) Program step 66 loads the Accumulator with the contents of Register 3
which contains the base (Step 06).  We'll use 8 as our example of the base
measurement.

(67) Program step 67 adds the contents of Register 3 (which contains the base
measurement of 8 in our example) to the contents of the Accumulator which now
also contains 8.

(68) The contents of the Accumulator (8+8=16) are stored in Register 5.

(69) The Accumulator is loaded with the contents of Register 4 which contains
the height.  We'll use 3 as our example.  This data was entered into Register
4 in Program step 07.

(70) In Program step 70, the Accumulator is decremented by 1.  (Remember, in
multiplying, the multiplier is decremented by 1 with each addition operation
until the multiplier equals 01).

(71) The contents of the Accumulator (now 2) are loaded into Register 4.

(72 through 73)  These instructions tell the computer to branch to Program
step 77 if the contents of the Accumulator are equal to the contents of
Register 1.  (Register 1 = 01).  This was accomplished in Program step 02.

(74) If the Accumulator does not equal 01 at Program step 72, the Accumulator
will move to Program step 75 and be loaded from Register 6 which contains 16.

(75 and 76)  Go to step 67.  The addition process is repeated until the amount
in the Accumulator is equal to the value of Register 1.  When this condition
is achieved, the computer will branch to Program step 77 as instructed by
Program steps 72 and 73.

(77) The Accumulator is loaded from Register 5. (Register 5 now equals 24
which is the answer.)

(78)  Program step 78 instructs the computer to return from subroutine.

This returns the computer to program step 15 which unpacks the contents of
Register 5.

Program steps 16 and 17 output the answer to the screen.

Program step 18 tells the computer to go to the blanking operation at program
step 58.

Program steps 58 through 63 output blank spaces that erase the old problem and
make room for a new one.

Program step 64 tells the computer to return to step 00 and to get ready to
solve a new problem.


Now we'll see how this program computes the area of a triangle (Base * Height
/ 2 = Area of Triangle)  For our example, we'll use 6 as the base and 2 as the
height.

This time we will choose 2 (triangle routine) at Program step 08 to load into
the Accumulator.  Since Program steps 09 and 10 do not apply, the computer
will jump to Program step 11.

Program step 11 instructs the Odyssey2 to branch to program step 20 for the
triangle routine.

Program 20 instructs the Odyssey2 to branch to step 66 for the multiply
routine.

Program steps 66 through 75 perform the addition operations and continue to
loop until the Accumulator equals Register 1 (01).  Then the Odyssey2 branches
to step 77.

Program step 77 loads the Accumulator with Register 5, which holds the answer
for B * H or 6 * 2 = 12.  We must now divide this answer by 2 to find the area
of a triangle.

Program step 78 instructs Odyssey2 to return to the program step immediately
following the subroutine from which it branched originally.

Program step 22 - a pause is implemented.

Program step 23 stores Accumulator (which contains 12) in Register 3.  This
now becomes the dividend.

Program steps 24 and 25 load Register 4 with 02; this becomes the divisor.

Program steps 26 ane 27 load Register 7 with 00.  This is the initialization
operation, since this Register will hold the sum of the subtraction
operations.  ("Initialization" was first introduced at the beginning of the
One Digit Division Program.)

Program step 28 loads Accumulator from Register 4 (which contains the divisor,
2).

Program step 29 subtracts Accumulator from Register 3 (which contains the
dividend, 12).

Program step 30 stores the difference (12 - 2 = 10) in Register 3; Register 3
= 10.

Program step 31 loads Accumulator from Register 7; Register 7 = 00.

Program step 32 adds one to the Accumulator.  Remember, this is done to keep
track of the number of times we subtract the divisor from the dividend.

Program step 33 stores sum in Register 7; Register 7 = 01.

Program step 34 loads Accumulator from Register 3; Register 3 = 10, dividend.

Program steps 35 and 36 order a branch to step 54 if Accumulator equals 00.

Program step 37 loads Accumulator from Register 4; Register 4 = 2, divisor.

Program steps 38 and 39 branch to step 42 if Register 3 is less than the
Accumulator.

Program step 40.  If the Odyssey2 has not branched at this point to another
step number, this instruction loops the Odyssey2 back to Program step 29, so
that additional subtraction operations can be performed.

At Program step 35, the computer, after completing the subtraction operations
so that the Accumulator and Register 3 (the dividend) equal 00, branches to
step 54.*  At Program step 54, the Accumulator is loaded from Register 7
(which contains the number of times we subtracted the answer).  Program step
55 then unpacks this answer and Program steps 56 and 57 output the answer to
the screen.  Blanks are outputed, since in this example there is no remainder,
and at step 64, the Odyssey2 is instructed to return to Program step 00 in
preparation for a new problem.

Now you're ready to enter the program into your Odyssey2.  Be sure to turn the
power off and on to erase any previous data.

*Note: If there had been a remainder, the computer would have branched at
Program step 38 to step 42 and when the answer was unpacked and displayed on
the screen, a (+R) would also have been displayed.


"Go to Subroutine" and "Return"


     Hex    Assembler
Step Code   Code       Byte   Remarks
----------------------------------------------------------------------------
00   6B 00  LDV.B.00    2     Reg. B = 00 (Positioning)
02   61 01  LDV.1.01    2     Area of rectangle - select (1)
04   62 02  LDV.2.02    2     Area of triangle - select (2)
06   73     INP.3       1     Input value (base) to Reg. 3
07   74     INP.4       1     Input value (height) to Reg. 4
08   04     INA         1     Select 1 or 2
09   31 13  BEQ.1.13    2     Go to rectangle routine
11   32 20  BEQ.2.20    2     Go to triangle routine
13   14 66  GTS.66      2     Go to multiply subroutine
15   B5     UNP.5       1     Unpack Reg. 5 and 6
16   C5     OUT.5       1     Output 1st digit
17   C6     OUT.6       1     Output 2nd digit
18   12 58  GTO.58      2     Go to blanking operation
20   14 66  GTS.66      2     Go to multiply subroutine
22   00     NOP         1     No operation (pause)
23   A3     STO.3       1     Store Accum. in Reg. 3
24   64 02  LDV.4.02    2     Load Reg. 4 with 02
26   67 00  LDV.7.00    2     Load Reg. 7 with 00
28   94     LDA.4       1     Load Accum. from Reg. 4
29   D3     SUB.3       1     Subtract Accum. from Reg. 3
30   A3     STO.3       1     Store difference in Reg. 3
31   97     LDA.7       1     Load Accum. from Reg. 7
32   03     INC         1     Add one to Accum.
33   A7     STO.7       1     Store sum in Reg. 7
34   93     LDA.3       1     Load Accum. from Reg. 3
35   13 54  BRZ.54      2     Branch to step 54 if A = 0
37   94     LDA.4       1     Load Accum. from Reg. 4
38   53 42  BLS.3.42    2     Branch to step 42 if Reg. 3 is less than Accum.
40   12 29  GTO.29      2     Go to step 29
42   97     LDA.7       1     Load Accum. from Reg. 7
43   B8     UNP.8       1     Unpack Reg. 8 and Reg. 9
44   C8     OUT.8       1     Output 1st digit
45   C9     OUT.9       1     Output 2nd digit
46   6E 10  LDV.E.10    2     Load Reg. E with Symbol (+)
48   6F 13  LDV.F.13    2     Load Reg. F with Symbol (R)
50   CE     OUT.E       1     Output (+)
51   CF     OUT.F       1     Output (R)
52   12 58  GTO.58      2     Go to step 58
54   97     LDA.7       1     Load Accum. from Reg. 7
55   B8     UNP.8       1     Unpack Reg. 8 and Reg. 9
56   C8     OUT.8       1     Output 1st digit
57   C9     OUT.9       1     Output 2nd digit
58   6E 0C  LDV.E.0C    2     Load Reg. E with a blank
60   6F 0C  LDV.F.0C    2     Load Reg. F with a blank
62   CE     OUT.E       1     Output blank
63   CF     OUT.F       1     Output blank
64   12 00  GTO.00      2     Go to step 00
66   93     LDA.3       1     Load Accum. from Reg. 3
67   E3     ADD.3       1     Add Reg. 3 to Accum
68   A5     STO.5       1     Store Accum. in Reg. 5
69   94     LDA.4       1     Load Accum. from Reg. 4
70   02     DEC         1     Decrement Accum. by 1
71   A4     STO.4       1     Store Accum. in Reg. 4
72   31 77  BEQ.1.77    1     If Accum. = Reg. 1, branch to step 77
74   95     LDA.5       1     Load Accum. from Reg. 5
75   12 67  GTO.67      2     Go to step 67
77   95     LDA.5       1     Load Accum. from Reg. 5
78   07     RET         1     Return to subroutine


One Digit Addition Flash Card


When you enter this program, a Flash Card addition game will appear on your
television set.  An unsolved addition problem flashes on the screen.  You
enter the solution through the keyboard.  If the answer is less than 10,
preface the number with a 0.

This program is different from the Flash Card game which is already
programmed in the computer.  In this program, the old problem is erased
automatically and a new problem is displayed on the screen.  There is also a
rather interesting reward for entering the correct answer.  Program steps 45
through 61 input a computerized musical comedy production number.  Program
steps 70 through 78 are the rests (pauses) in the melody.

Program step 26 is a packing operation.  The data from Register 3 and
Register 4 is combined and loaded into the Accumulator.

Program steps 62 through 69 reset Register B to 00 so that it's ready for
the next problem.

Program steps 62 through 69 reset Register 3 to 00 so that it's ready for
the next problem. [this line is an error in the doc]


One Digit Addition Flash Card

     Hex    Assembler
Step Code   Code       Byte   Remarks
----------------------------------------------------------------------------
00   6A 0C  LDV.A.0C    2     Load a blank into Reg. A
02   68 10  LDV.8.10    2     Load a (+) sign into Reg. 8
04   69 2B  LDV.9.2B    2     Load an (=) sign into Reg. 9
06   6C 2D  LDV.C.2D    2     Load (N) into Reg. C
08   6D 17  LDV.D.17    2     Load (O) into Reg. D
10   08     RND         1     Load Accum. with random number
11   B0     UNP.0       1     Separate digits
12   6B 00  LDV.B.00    2     Set output position
14   C0     OUT.0       1     Output first digit
15   C8     OUT.8       1     Output (+) sign
16   C1     OUT.1       1     Output second digit
17   00     NOP         1     A no operation instruction must follow every
                              third output instruction in a row
18   C9     OUT.9       1     Output (=) sign
19   90     LDA.0       1     Load Accum. from Reg. 0
20   E1     ADD.1       1     Add Reg. to the Accum.
21   A2     STO.2       1     Store sum in Reg. 2
22   73     INP.3       1     Input first digit guess
23   C3     OUT.3       1     Output first digit guess
24   74     INP.4       1     Input second digit guess
25   C4     OUT.4       1     Output second digit guess
26   83     PAK.3       1     Combine digits.  This is a packing operation.
27   CA     OUT.A       1     Output blank
28   32 45  BEQ.2.45    2     If correct guess...buzz
30   CC     OUT.C       1     Output (N)
31   CD     OUT.D       1     Output (O)
32   6B 04  LDV.B.04    2     Set output position to 04
34   73     INP.3       1     Input first number of second guess
35   C3     OUT.3       1     Output first number
36   CA     OUT.A       1     Output blank
37   CA     OUT.A       1     Output blank
38   00     NOP         1     No operation
39   CA     OUT.A       1     Output blank
40   CA     OUT.A       1     Output blank
41   6B 05  LDV.B.05    2     Set output position to 05
43   12 24  GTO.24      2     Go to step 24
45   05     SIG         1     Buzz
46   14 70  GTS.70      2     No sound
48   05     SIG         1     Buzz
49   05     SIG         1     Buzz
50   05     SIG         1     Buzz
51   14 70  GTS.70      2     No sound
53   05     SIG         1     Buzz
54   14 70  GTS.70      2     No sound
56   14 70  GTS.70      2     No sound
58   05     SIG         1     Buzz
59   14 70  GTS.70      2     No sound
61   05     SIG         1     Buzz
62   6B 00  LDV.B.00    2     Set position to 00
64   CA     OUT.A       1     Output blank
65   9B     LDA.B       1     Load Accum. from Reg. B
66   13 10  BRZ.10      2     If Accum. = 0, the computer branches to step 10
68   12 64  GTO.64      2     Go to step 64
70   67 00  LDV.7.00    2     Load Reg. 7 with 00
72   6E 75  LDV.E.75    2     Load Reg. E with 75
74   9E     LDA.E       1     Load Accum. from Reg. E
75   00     NOP         1     No operation
76   02     DEC         1     Subtract 1 from Accum.
77   27 75  BNE.7.75    2     Branch if Accum. is not = to Reg. 7 which
                              contains 00
79   07     RET         1     Return from subroutine


Three Ways to Enter and Output a Letter

These three sample programs are presented to show you the three different
instructions which can be used to input and output a letter on the screen.

For the first example, we have chosen to input and display the letter "H"
or 1D in HEX Code.  With this type of program, whatever is loaded into the
register and is outputed to the screen will remain on the screen.  You cannot
change it.  With this program, you could enter a complete message and have it
remain on the screen.

The second example uses the instructions, "Input to a Register" and "Output
from a Register," but does not designate any particular value.  Thus, once the
program is entered, any value can be entered and it will be displayed on the
screen.

The third example is similar to the second in that any value may be
entered, but it is inputed to the Accumulator rather than to a register.

You will note, in all three examples, the last instruction was "Input to a
Register" which was used as a pause since no output instruction was indicated,
thus only one keyboard depression could be made.  Now, try this - using
example two or three, program the appropriate instruction sets in order to
create a loop so that all 11 positions on the screen may be used.  (Hint!
Refer bback to the addition programs.  Check to see how they let you keep
entering one problem after another by returning to a previous program step.)


Three Ways to Enter and Output a Letter (For this example, use "H")

     Hex    Assembler
Step Code   Code       Byte   Remarks
-------------------------------------------------------------

A

00   6B 00  LDV.B.00    2     Positioning
02   60 1D  LDV.0.1D    2     Load Reg. 0 with H
04   C0     OUT.0       1     Output Reg. 0 = H
05   71     INP.1       1     Input to Reg. 1 (used as pause)

B

00   6B 00  LDV.B.00    2     Positioning
02   70     INP.0       1     Input Reg. 0
03   C0     OUT.0       1     Output Reg. 0
04   71     INP.1       1     Input Reg. 1 (pause)

C

00   6B 00  LDV.B.00    2     Positioning
02   04     INA         1     Input Accum.
03   0B     OTA         1     Output Accum.
04   71     INP.1       1     Input REg. 1 (pause)


Six Letter Guess

After Being entered, this program allows you to enter a six letter word into
the Odyssey2.  Six dots appear on the screen and your opponent enters a
letter.  If it is used in the word, it appears on the screen in the correct
position.  If the letter does not appear in the word, nothing happens.

Let's look at some of the program steps in detail:

Program step 00 used as a flag or reference position.  01 is loaded into
Register 7.  01 was chosen rather than 00 because 01 can only mean the decimal
number 1 and nothing else, while 00 can be a number or the instruction "No
Operation."

Program steps 04, 05, and 06 input 1st letter into Register 9, load a dot
into Register 1, output Register 1 to screen.  THis is an initialization
process and steps 07 through 27 are the same.  This is done so that the six
dots appear on the screen when the word is first inputed.  Note the Register
Use column.

Program steps 28 through 37 position Odyssey2 to 00 each time a guess is
taken and output to the screen either the correct letter guessed or a dot.

Program steps 38 and 39 instruct Odyssey2 to return to 00 if Accumulator
equals the contents of Register 7.  The computer is now ready for a new game.
(Note: This is a flag or reference point.)

Program step 40 inputs a guess to the Accumulator.  It is compared to each
register in Program steps 41 through 52.

Program steps 53 and 54 instruct Odyssey2 to go to Program step 71 if a
letter in the word is missing.

Program steps 71 and 72 load Register 8 with a dot.

Program step 73 loads the Accumulator from Register 8.

Program steps 74 through 85 instruct Odyssey2 to branch to Program step 28
if any register (1 through 6) is equal to the Accumulator (in other words, if
the register still remains a dot.)

Program steps 86 and 87 load Register 7 with a 2B (=).  This is a flag.*

Program step 88 loads the Accumulator from Register 7.

Program steps 89 and 90 sound the buzz which indicates the word has been
displayed correctly.

Program steps 91 and 92 instruct Odyssey2 to go to step 28 for positioning.

Program steps 38 and 39 instruct Odyssey2 to return to 00 if Accumulator =
Register 7.

Program step 00 loads Register with 01 and game continues.

* Note: the 2B (=) sign was used as a flag in this instance: however, any
sign could have been used instead.


Six Letter Guess


     Hex    Assembler
Step Code   Code       Byte   Remarks                   Register/Use
-----------------------------------------------------------------------
00   67 01  LDV.7.01    2     Reg. 7 is loaded with     01
                              reference position (flag)
02   6B 00  LDV.B.00    2     Positioning               1 - 1st dot
04   79     INP.9       1     Input 1st letter          2 - 2nd dot
05   61 27  LDV.1.27    2     Read 1st dot              3 - 3rd dot
07   C1     OUT.1       1     1st dot on screen         4 - 4th dot
08   7A     INP.A       1     Input 2nd letter          5 - 5th dot
09   62 27  LDV.2.27    2     Read 2nd dot              6 - 6th dot
11   C2     OUT.2       1     2nd dot on screen         7 - 01 (flag)
12   7C     INP.C       1     Input 3rd letter          8 - 7th dot
13   63 27  LDV.3.27    2     Read 3rd dot              9 - 1st letter
15   C3     OUT.3       1     3rd dot on screen         A - 2nd letter
16   7D     INP.D       1     Input 4th letter          B - Positioning
17   64 27  LDV.4.27    2     Read 4th dot              C - 3rd letter
19   C4     OUT.4       1     4th dot on screen         D - 4th letter
20   7E     INP.E       1     Input 5th letter          E - 5th letter
21   65 27  LDV.5.27    2     Read 5th dot              F - 6th letter
23   C5     OUT.5       1     5th dot on screen
24   7F     INP.F       1     Input 6th letter
25   66 27  LDV.6.27    2     Read 6th dot
27   C6     OUT.6       1     6th dot on screen
28   6B 00  LDV.B.00    2     Position on screen
30   C1     OUT.1       1     Put dots on screen
31   C2     OUT.2       1     Put dots on screen
32   C3     OUT.3       1     Put dots on screen
33   00     NOP         1     No operation
34   C4     OUT.4       1     Put dots on screen
35   C5     OUT.5       1     Put dots on screen
36   C6     OUT.6       1     Put dots on screen
37   00     NOP         1     No operation
38   37 00  BEQ.7.00    2     Reset
40   04     INA         1     Input guess to Accum.
41   39 55  BEQ.9.55    2     Letter in word
43   3A 58  BEQ.A.58    2     Letter in word
45   3C 61  BEQ.C.61    2     Letter in word
47   3D 64  BEQ.D.64    2     Letter in word
49   3E 67  BEQ.E.67    2     Letter in word
51   3F 70  BEQ.F.70    2     Letter in word
53   12 71  GTO.71      2     Wrong guess
55   A1     STO.1       1     1st letter correct
56   12 43  GTO.43      2     Check next position
58   A2     STO.2       1     2nd letter correct
59   12 45  GTO.45      2     Check next position
61   A3     STO.3       1     3rd letter correct
62   12 47  GTO.47      2     Check next position
64   A4     STO.4       1     4th letter correct
65   12 49  GTO.49      2     Check next position
67   A5     STO.5       1     5th letter correct
68   12 51  GTO.51      2     Check next position
70   A6     STO.6       1     6th letter correct
71   68 27  LDV.8.27    2     Load Reg. 8 with dot
73   98     LDA.8       1     Accum. is loaded from Reg. 8
                              which contains a dot
74   31 28  BEQ.1.28    2     Position (Step 28)
76   32 28  BEQ.2.28    2     Position (Step 28)
78   33 28  BEQ.3.28    2     Position (Step 28)
80   34 28  BEQ.4.28    2     Position (Step 28)
82   35 28  BEQ.5.28    2     Position (Step 28)
84   36 28  BEQ.6.28    2     Position (Step 28)
86   67 2B  LDV.7.2B    2     Set flag to (=)
88   97     LDA.7       1     Accum. loaded from Reg. 7
                              which contains 01
89   05     SIG         1
90   05     SIG         1
91   12 28  GTO.28      2     Positioning


Message

After being entered, this program allows you to press any number between 1 and
6 to call a programmed message to the screen.  In the program as it is
written, we have entered six messages.  After studying the program, you can
enter your own messages.

You will note the first Program steps, 00 and 01, are load a value into
Register 0 and the value is 90.  You will note that Program step 90 is the "No
Operation" instruction after the last message, and that program steps 91
through 96 are a relocation table.  The Hex Code at each of the program steps
is the first program step number of each of the messges[sic].  It is this
first instruction, "load a value into Register 0 and the vlaue is 90" which
allows you to select any number between 1 and 6 to call a message to the
screen.  Let's look at a few of the other instructions in the program.

Program steps 02 and 03 load Register 1 with 0C (blank).  This blank will
be used as the space between words in messages which have more than one word.

Program step 04 inputs to the Accumulator; you may select 1,2,3,4,5,6, on
the keyboard in order to call to the screen any one of six messages and
whichever you choose will be inputed to the Accumulator.

Program step 05 - add Register 0 to Accumulator.  In other words, if we had
chosen number 2, the contents of Register 0 (which are 90) are added to the
Accumulator (which is 2), thus 92 is now in the Accumulator.

Program step 06 - store Accumulator in Register C; Register C now equals 92.

Program step 07 - Register C moves the program counter to Program step 92,
and the contents at Program step 92 (which are 36) are loaded into the
Accumulator.  This is the "Move" instruction or "Load Accumulator from a
program step."  Register C is always used with this instruction.

Program step 08 - Store Accumulator (36) in Register C; C now equals 36.

Program steps 09 and 10 load Register B (positioning) with the value 00
(the furthest left position).

Program steps 11 and 12 load Register 2 with the number 11 (the number of
positions on the screen).

Program steps 13 and 14 load Register 3 with 00 to be used as a reference.

Program step 15 - load the Accumulator from Register 1; Register 1 equals a
blank.  This begins the loop which erases an old message from the screen in
preparation for a new message.  You will note program steps 15 through 21,
load the Accumulator with a blank, output the blank, load the Accumulator from
Register 2(11), decrement the Accumulator by 1, store the result in Register
2, and the Odyssey2 branches to step 15 if the Accumulator is not equal to
Register 3 (00).  Remember, when erasing, each of the 11 positions must be
filled with a blank.

Program steps 22 and 23 load Register B with 00 (furthest left position).
This is used to position Register B in preparation for a new message.

Program step 24 takes the contents of Register C (36), moves to that
program step (36) and loads the contents at that program step (14) into the
Accumulator.

Program steps 25 and 26: If the Accumulator equals 00 at this point, the
Odyssey2 would branch to Program step 04, and prepare itself for a new
message.  If the Accumulator contains a value (as in this example, it contains
14), then the Odyssey2 steps to Program step 27.

Program step 27 outputs the contents of the Accumulator to the screen; a
"T" appears.  Refer to your Hex Code chart.

Program steps 28 and 29 instruct Odyssey2 to go to step 24 and loop through
the previous instructions to display message.*  When the message is completed
(note at the end of each message, there is a no operation instruction, 00),
and the Odyssey2 steps to Program step 25, the Accumulator will be equal to
Register 3 (00), and the Odyssey2 will brank to Program step 04 in preparation
for a new message.

*Note: When repeating the loop at Program step 24, the contents of Register C
remain the same (36); however, the program counter increments by one each time
so that the appropriate program step is reached.


Message

     Hex    Assembler
Step Code   Code       Byte   Remarks                       Register/Use
--------------------------------------------------------------------------
00   60 90  LDV.0.90    2     Location table                0 - 90
02   61 0C  LDV.1.0C    2     A blank is loaded into Reg. 1 1 - 0C (blank)
04   04     INA         1     Press 1,2,3,4,5, or 6         2 - 0B (11)
05   E0     ADD.0       1     Add Reg. 0 to Accum           3 - 00
06   AC     STO.C       1     Contents of Accum. are stored 4
                              in Reg. C
07   09     MOV         1     Accum. is loaded with         5
                              contents of Reg. C which is a
                              program step number
08   AC     STO.C       1     Contents of Accum. is stored  6
                              in Reg. C
09   6B 00  LDB.B.11    2     Load Reg. B with 00           7
                              (positioning)
11   62 11  LDV.2.0B    2     Load Reg. 2 with the number   8
                              11 (positions on screen)
13   63 00  LDV.3.00    2     Load Reg. 3 with 00           9
                              (used as a reference)
15   91     LDA.1       1     Load Accum. from Reg. 1       A
16   0B     OTA         1     Output blank from Accum.      B
17   92     LDA.2       1     Load Accum. from Reg. 2       C
18   02     DEC         1     Decrement Accum. by 1         D
19   A2     STO.2       1     Store contents of Accum       E
                              in Reg. 2
20   23 15  BNE.3.15    2     Loop to program step 15 and   F
                              output more blanks if Accum.
                              is not equal to Reg. 3
22   6B 00  LDV.B.00    2     Positioning of Reg. B
24   09     MOV         1     Reg. C moves to program step
                              and loads contents at the
                              program step into the Accum.
25   33 04  BEQ.3.04    2     Restart - if Accum. equals 00,
                              return to step 04
27   0B     OTA         1     Output contents of Accum.
28   12 24  GTO.24      2     Go to step 24 to display message
30   1D     *           1     Output (H)
31   12     *           1     Output (E)
32   0E     *           1     Output (L)
33   0E     *           1     Output (L)
34   17     *           1     Output (O)
35   00     *           1     End Mess. 1
36   14     *           1     Output (T)
37   20     *           1     Output (A)
38   1F     *           1     Output (K)
39   12     *           1     Output (E)
40   0C     *           1     Blank
41   20     *           1     Output (A)
42   0C     *           1     Blank
43   0E     *           1     Output (L)
44   17     *           1     Output (O)
45   17     *           1     Output (O)
46   1F     *           1     Output (K)
47   00     *           1     End Mess. 2
48   13     *           1     Output (R)
49   12     *           1     Output (E)
50   26     *           1     Output (M)
51   20     *           1     Output (A)
52   13     *           1     Output (R)
53   1F     *           1     Output (K)
54   20     *           1     Output (A)
55   25     *           1     Output (B)
56   0E     *           1     Output (L)
57   12     *           1     Output (E)
58   00     *           1     End Mess. 3
59   2D     *           1     Output (N)
60   12     *           1     Output (E)
61   11     *           1     Output (W)
62   0C     *           1     Blank
63   1B     *           1     Output (F)
64   17     *           1     Output (O)
65   13     *           1     Output (R)
66   0C     *           1     Blank
67   07     *           1     Output (7)
68   08     *           1     Output (8)
69   00     *           1     End Mess. 4
70   18     *           1     Output (Q)
71   15     *           1     Output (U)
72   12     *           1     Output (E)
73   19     *           1     Output (S)
74   14     *           1     Output (T)
75   16     *           1     Output (I)
76   17     *           1     Output (O)
77   2D     *           1     Output (N)
78   19     *           1     Output (S)
79   0D     *           1     Output (?)
80   00     *           1     End Mess. 5
81   23     *           1     Output (C)
82   17     *           1     Output (O)
83   26     *           1     Output (M)
84   12     *           1     Output (E)
85   0C     *           1     Blank
86   25     *           1     Output (B)
87   20     *           1     Output (A)
88   23     *           1     Output (C)
89   1F     *           1     Output (K)
90   00     *           1     End Mess. 6
91   30     *           1     Location table
92   36     *           1     Location table
93   48     *           1     Location table
94   59     *           1     Location table
95   70     *           1     Location table
96   81     *           1     Location table

*When entering single letters and numbers, the Hex Code only is used,
since there is no Assembler Code for them.

You have now had some experience in entering programs and should have some
insight into how a computer "thinks."

You can get a deeper understanding of your Odyssey2's logic processes by
trying to enter these programs without using the references.

First, go back and review one of the shorter programs.  Enter it into the
computer.  Use your reference at this stage - but study it for sequence of
events, logic patterns and flow.  Then, go to one of the blank program sheets
in the back of this book and try writing the program from scratch.  No
peeking.

Here are some things you'll want to keep in mind.

Odyssey2 has 16 registers.  Each register has room for 8 bits of
information.

Your computer has a capacity of 99 program steps.  There are 11 positions
available on the screen.  The contents of Register B position data on the
screen.

You can only output data to the screen from a register or the Accumulator.

Keep the fold-outs open so you can refer to the instruction sets and check
your data traffic patterns.

As you begin to write these programs by yourself, you'll get used to
thinking along a computer's logic lines.  You may want to try writing
variations of the programs in this book.  You may even want to try creating
original programs.  If something doesn't work, try it another way.  You're
playing with electronic building blocks that have endless combinations of
possibilities.

Once you feel you have a good understanding of how Odyssey2 does its
computing, consider yourself graduated with high honors.  If there's a
computer store in your area, drop in and visit.  You'll find friendly
professionals who are always ready to talk computers and share knowledge.

And you now know far more than most people who walk in the door.


Operating Mode Review

There are eight operating modes in the Odyssey2.  They are:

Command     Assembler
Execution   Hex Input
Display     Input
Program     Roll

Let's look at each in detail and refer to the operation diagram on the
fold-out as you read about each mode.


Command Mode

To enter the Command Mode, you may press "Reset" or "Clear" if you are in
any of the following modes:

Assembler
Display
Hex Input

If you are in the Execution Mode, to enter the Command Mode, press "Reset."

Once in the Command Mode, you may enter the following modes:

Execution
Display
Program

by pressing:
E - To enter the Exection Mode.  Program execution will begin with step00.
You are ready to play your game, write your message, solve your problem, etc.
if you have already entered your program.

or by pressing:
C - To enter the Continue Mode.  This mode is used to locate a problem within
a register.  For example, let's assume we have a 40 step program that is not
working correctly.  A branch decision was made at some lower step number and
we would like to see if the correct branch was taken to the step number we had
indicated, say Program step 14.  Using the Roll Mode, we would move to Program
step 14 and replace the Op Code at that step number with a halt statement (Op
Code FF).  To examine the contents of the program counter (which would contain
the Program step 14, thus informing us of the correct branch), we would press
"Clear" which returns us to the Command Mode.  We now press (P) to enter the
Program Mode, then press (M) to enter the Hex Input Mode, and then press (R)
to enter the Roll Mode.  We no must roll up (U) from step 00 to step 14 where
the FF statement is located and replace it with the original Op Code.  We may
now place an FF statement at some other step to check another part of the
program.  Please note that only one FF statement at a time can be present in
the program.

or by pressing:
D - To enter the Display Mode (to be explained in detail later).

or by pressing:
P - To enter the Program Mode (to be explained in detail later).


Dispaly Mode

To enter the Display Mode, press (D) from the Command Mode.  In this mode,
you may display on the screen any register you wish to review.  This mode is
often used to troubleshoot problems, since you can check the contents of each
register.

To check the registers you press:

0 To display the contents of Register 0
1 To display the contents of Register 1
2 To display the contents of Register 2
3 To display the contents of Register 3
4 To display the contents of Register 4
5 To display the contents of Register 5
6 To display the contents of Register 6
7 To display the contents of Register 7
8 To display the contents of Register 8
9 To display the contents of Register 9
A To display the contents of Register A
B To display the contents of Register B
C To display the contents of Register C
D To display the contents of Register D
E To display the contents of Register E
F To display the contents of Register F
P To display the contents of the Program Counter
S To display the contents of the Subroutine Counter
X To display the contents of the Accumulator

To leave the Display Mode, press "Clear" or "Reset" to enter the Command
Mode.


Program Mode

[Picture of P button and CLEAR button on the keyboard]

To enter the Program Mode, press (P) from the Command Mode, or press
"Clear" if you are in the Roll Mode.

The Program Mode sets the Odyssey2 to accept a program.  From this mode,
press (A) to enter Assembler Language or press (M) to enter Hex Language (Op
Code).

To leave the Program Mode, press "Reset" and you will enter the Command
Mode, or you may leave the Program Mode by pressing (A) to enter the Assembler
Mode or by pressing (M) to enter the Hex Input Mode.


[Picture of A button on keyboard]
Assembler Mode

To enter the Assembler Mode, press (A) if you are in the Program Mode, or
press "Clear" if you are already in the Input Momde.

Once you have pressed (A), you are in the Assembler Mode and you may now
press (I) to enter the Input Mode, or press (R) to enter the Roll Mode.

To leave the Assembler Mode, press "Clear" or "Reset" to enter the Command
Mode, or press any valid Assembler Mode command (i.e., [I] or [R]).  (Be sure
to refer to the fold-out operational diagram.)


[Picture of M button on keyboard]
Hex Input Mode

To enter the Hex Input Mode, press (M) if you are in the Program Mode or
press "Clear" if you are in the Input Mode.

Once in the Hex Input Mode, press (I) to enter the Input Mode, or press (R)
to enter the Roll Mode.

To leave Hex Input Mode, press "Clear" or "Reset" to enter Command Mode or
press any valid Hex Input Mode command (i.e., [I] or [R]).


[Picture of I button on keyboard]
Input Mode

To enter the Input Mode, press (I) if you are in either Assembler or Hex
Input Mode.

Once you are in the Input Mode, you may enter any assembler language
instruction if you have entered from the Assembler Mode, or you may enter any
HEX language instruction (Op Code) if you have entered from the Hex Input
Mode.  The Input Mode is the mode in which you will enter your program.

To leave the Input Mode, you may press "Reset" to enter the Command Mode,
or press "Clear" to enter the Assembler or Hex Input Mode.


[Picture of R button on keyboard]
Roll Mode

To enter the Roll Mode, press (R) if you are in either Assembler or Hex
Input Mode.

Once you are in the Roll Mode, you may press (U) to display the program
steps from 00 to 99, or you may press (D) to display the program steps from 99
to 00.  This mode is often used to check a program step to be sure it contains
the correct data.

To leave the Roll Mode, press "Clear" to enter the Assembler or Hex Input
Mode.

[Illustration of keyboard]

How a Computer Adds 1 + 1


|----------|
|          |
| 1 + 1 = ?|
------------
     ^
     |       1
|----------|------>|------| 1          |---------|0
|Keyboard  | +1|   |  Or  |----------->|   And   |-|
|          |---|-->|      |      |---->|         | |
------------ | |   --------      |     ----------- |
             | |                0|                 |
             | | |-------| 1 |-------|             |
             | ->|  And  |-->|  Not  |             |
             --->|-------| | |-------|             |
                           |                       |
                           |--------------------|  |
                                                |  |
                                                v  v
                      Symbol/Sound Generator |--------|
                      converts Binary 10 into|   10   |
                      decimal equivalent 2   |--------|
                                                 |
                                                 |
                                                 v
                                             |-----------|
                                             | 1 + 1 = 2 |
                                             |-----------|



Glossary


Glossary of Frequently Used Computer Terms


[Illustration of a person working at an old style computer, with an arrow
pointing at one of the tape drives]

Accumulator.  A working register within a computer.  It is a small memory
device that provides temporary data storage and/or instruction storage for the
ALU.  It can also store the result of the ALU's operation and may be used as
an operand source for the ALU.

Applications.  A job given to the computer to do.

Application Software.  Programs written for the computer.

Arithmetic Logic Unit (ALU).  A part of the Central Processing Unit (CPU).
The ALU accepts data from different sources, acts upon it, then outputs one
result.  It is in the ALU that all arithmetic and logic operations are
performed.  It is also known as the "number cruncher" since it's here that all
binary data is acted upon.

[Illustration of a 1 and a 0]

Binary Numbers.  A number based on two digits.  1 and 0.  With enough 1's and
0s, any number can be expressed.  The inside of a computer is basically a
series of on-off switches that turn on any electrical charge to express1.
They turn off the electrical charge to express 0.  A computer performs binary
calculations by sending these on-off signals thorugh logic gates which pass on
information according to the rules built into them.

The functions of these logic gates are called AND, OR and NOT.

This diagram demonstrates how a computer's logic circuit adds 1 and 1.

[An illustration, not the diagram referred to above, shows two arrows going
through a couple of gates and terminating at a third.  The diagram referred to
above is the flow chart reproduced above.]

1. Two electrical currents enter the logic circuit.  (Remember - the presence
of the electricity signals 1.  The absence signals 0.)

2. The incoming currents flow to the OR gate at the top and to the first AND
gate at the bottom.  The OR gate lets the current through because at least one
of the circuits is carrying an electrical charge.  The AND gate lets the
current through because both circuits are carrying a charge.

3. The current at the top heads to the second AND gate.  The bottom stream is
divided with one part flowing to the exit and the other part heading toward
the NOT gate.

4. A NOT gate is a "reverser."  It changes 1's to 0's and 0's to 1's.  The NOT
gate turns off the current flowing through it.

5. The second AND gate senses the absence of current from the NOT gate and the
presence of current coming to it from the OR gate.

6. Since one of the streams entering the second AND gate is charged and the
other is not, the second AND gate will not allow any current to pass to the
exit.

7. The original two electrical currents representing 1 and 1 come out of the
logic circuit as only one stream o electrical current.  This is expressed as 1
and 0 - the binary equivalent of 2.

[Sideways illustration says 4 = 0100]

Computers operate only on binary numbers.  A computer can add, subtract,
multiply (by adding the same number repeatedly), and divide (by using
subtraction and addition).  When a computer adds and subtracts binary numbers,
there are several rules which it follows:

Binary Addition:

0   0   1   1
0  +1  +0  +1
-   -   -   -
0   1   1   0 with a carry of 1

A carry bit is produced from the addition of 1+1.  Binary carries are treated
in the same way as decimal carries; they are carried to the left.

Example:

              (1)  (1)(1)(1)
 9 =  0  0  0  0    1  0  0  1
+7 =  0  0  0  0    0  1  1  1
------------------------------
16 =  0  0  0  1    0  0  0  0


Binary Subtraction:

1. All ones in the subtrahend are changed to zeros and all zeros are changed
to ones.

2. A one is then added to the least significant bit of the new subtrahend.

3. Add the result to the minuend and ignore the carry bit, if there is one.

Example: 10 = 0000 1010 minuend
         -5 = 0000 0101 subtrahend
         -------------------------
          5 =

Rule 1: 0000 0101 becomes 1111 1010

Rule 2: 1111 1010
       +        1
       ----------
        1111 1011

Rule 3: 0000 1010
       [phone]
       ----------
        0000 0101

Listed below are some binary numbers and their decimal equivalents.

Try adding and subtracting in binary.  It really works.

1=0001  5=0101    9=1001   13=1101
2=0010  6=0110   10=1010   14=1110
3=0011  7=0111   11=1011   15=1111
4=0100  8=1000   12=1100   16=0001 0000

Basic. Beginners All-Purpose Symbolic Instruction Code.  This is one of the
simplest programming languages and is in general use on many computers.

Bit. The basic unit of information used by a computer.  A bit is a binary
number.  1 or 0.  A simple pocket calculator may store less than a hundred
bits of information.  A large computer may have somewhere between a billion
and a trillion bits in storage.

Byte. A byte is eight bits on smaller computers, such as your Odyssey2.  A
byte can be twelve, sixteen or more bits on larger computers.


[Illustration of a chip]

Chip.  Nickname for Integrated Circuit. (IC)

Cobol. Common Business-Oriented Language.   A computer programming language
used widely in the business world.

Computer System.  The computer and all of its related hardware.  Your Odyssey2
system consists of the console, the computer cartridge and your TV - the video
terminal.

Control Unit.  The internal part of a computer that directs the binary
traffic.

Core Memory.  The internal memory of a computer.  Today, this memory consists
of Integrated Circuits (IC's).  In the old days, the core memory was stored on
magnetic cores made from tiny rings of magnetic material strung on a grid of
fine wire.

Central Processing Unit (CPU). This is the brain of the computer.  The CPU of
your Odyssey2 is contained on a microprocessor which can make over 1,000,000
electronic decisions every second.

[Illustration shows an asterisk]

Cursor.  A visual indicator on the video display terminal of some computers
that signals where a character must be corrected or the position where data
should be entered.  It is usually a star or an asterisk.

Data.  Refers to all letters, numbers, symbols and facts which can be
processed or used by a computer.

External Memory.  That memory used by the computer which is not stored within
the computer itself.  External memory is usually stored on cassette tape,
floppy or hard disk, or paper tape.

[Illustration shows rainbow colored paper tape]

Firmware.  A combination of hardware and software.  This term is generally
used in reference to software stored permanently on Read Only Memory chips
(ROM).

Floppy Disk.  It's thin, flexible and looks like a square record - a storage
device that typically holds more than 250,000 eight bit bytes of information.

Fortran.  FORmula TRANslator.  The most widely used scientific computer
programming language.

Hardware.  The physical devices that form a computer system - including all
mechanical, magnetic, electronic, electromechanical and electric components.
"Software" contains the instructions that tell all this what to do.

High-Level Language.  Software that makes it possible to program a computer in
more or less plain English.  Basic, Cobol and Fortran are all examples.

Input.  The data entered into computers.

Integrated Circuit (IC).  Many hundreds of electronic circuits on a single
chip of silicon.  This circuitry can be contained in less than a quarter inch
square and can make more than one million electronic decisions per second.
There are no moving parts.  It is theoretically possible for an integrated
circuit to function for thousands of years.

Internal Memory.  Memory located within the computer itself.

Interface.  Refers to the connection of one computer component to another.
When your TV is connected to your Odyssey2, it is interfaced.

Machine Language (Binary).  The instructions that a computer actually follows.
High-level language instructions in Basic, Cobol and Fortran are broken down
into machine language by the computer before they are executed.

Maxicomputers.  The gian computers used by governments, insurance companies
and businesses.

Microcomputers.  Small computers with Central Processing Units contained on
one single integrated circuit called a microprocessor.

[Picture of a circuit board.]

Microprocessor.  An integrated circuit that contains the complete central
processing unit for a computer.  Today, microprocessors are designed by
computer technology on a much larger than life scale.  Then, the circuits are
transferred photographically to a chip of silicon less than one quarter of an
inch square.

Nonvolatile Memory.  That part of a computer's memory that is not lost when
the computer is turned off.

Output.  Information that comes out of a computer and is displayed on a screen
(as with Odyssey2) or on a tape, floppy disc, print out, etc.

Programmable Read Only Memory (PROM).  The nonvolatile memory stored on an
integrated circuit from which the computer can read information.  The computer
cannot store information on a PROM.  The PROM is programmable because the
information stored on it can be changed one or more times depending on the
type of PROM.

Read Only Memory (ROM).  Permanent, nonvolatile memory stored on an integrated
circuit (IC).  The computer cannot store information on a ROM but can read the
information on it whenever necessary.  The ROM is not re-programmable and the
information on it cannot be modified or changed.

Random Access Memory (RAM).  This is the volatile memory of a computer which
is stored on integrated circuits.  The computer can read the data stored on
the chips - and new data can be entered onto the chips.  This information
disappears when the current is turned off.  Think of the ROM as the computer's
dictionary and encyclopedia and the RAM as the computer's scratch pad.  One is
printed and kept forever.  The other is used as a worksheet and thrown away.

[Some random text meant to represent software:
1.0C
LDV.B.0
63 00 09
6B 00
LDV.3.00
60 90
LDV.0.90
ADD.0]

Software.  All of the instructions used by the computer to perform its
functions.  This includes languages, operating systems and programs.


Instruction Sets

                   Hex   Assembler
Instruction        Code  Code   Byte Function
------------------------------------------------------------------------------

Input

Input to Register    7R  INP.R    1  To store a value from the keyboard
                                     (symbol or numeral) in a specified
                                     register.
Input to Accumulator 04  INA      1  To input data from the keyboard (symbol
                                     or numeral) into the Accumulator.
------------------------------------------------------------------------------

Output

Output from Register CR  OUT.R    1  To display the contents of a specified
                                     register on the television screen.  If
                                     you have a series of output instructions,
                                     one right after another, you must place a
                                     "No Operation" instruction after every
                                     third output instruction.
Output from Accumulator 0B OTA    1  To display data stored in the Accumulator
                                     on the television screen.
One second Buzz      05  SIG      1  To implement a one second buzz.
-------------------------------------------------------------------------------

Change Accumulator Contents

Set to 0             01  CLR      1  To clear Accumulator and set its contents
                                     to 0.
Subtract 1           02  DEC      1  To decrement the contents of the
                                     Accumulator by one.
Add 1                03  INC      1  To increment the contents of the
                                     Accumulator by one.
Load with Random No. 08  RND      1  To load Accumulator with a random number
                                     from 00 to 99.
Load from Program Step 09 MOV     1  To load Accumulator with the contents
                                     (two-digit value) contained in the
                                     program step specified by Register C.
                                     When using the MOV instruction in a
                                     program, Register C must remain empty.
                                     In other words, you should not program
                                     any value in Register C.
Combine 2 digits     8R  PAK.R    1  To combine two digits from two specified
                                     registers in the Accumulator.  This
                                     instruction is used when working with
                                     numbers.  Since the microprocessor reads
                                     the numbers in Binary, we must instruct
                                     it to combine two digits in order to
                                     produce and display a base 10 number.
                                     The first regstier must always contain a
                                     number less than ten.
Separate 2 digitts   BR  UNP.R    1  To separate two digits in the Accumulator
                                     and store them in two specified registers.
Load from Register   9R  LDA.R    1  To load the Accumulator with the contents
                                     of a specified register.
Add Register         ER  ADD.R    1  To add the contents of a specified
                                     Register (R) to the contents of the
                                     Accumulator and to store the result in the
                                     Accumulator.  If the result is larger
                                     than two digits, only the lowest two
                                     digits will be kept.
-------------------------------------------------------------------------------

Change Register Contents

Store Accumulator    AR  STO.R    1  To store contents of the Accumulator in a
                                     specified register.

Load A Value         6RNN LDV.R.NN 2 To load a value (NN) into a specified
                                     register (R).  Registers may be 0 through
                                     9 or A through F.
-------------------------------------------------------------------------------

Control Execution Order

No Operation         00  NOP      1  To implement a delay in execution of the
                                     program.  Can be used when writing a
                                     program to utilize several program steps,
                                     so that when checking the program, if an
                                     extra instruction step is needed, several
                                     will be vacant.
Halt                 FF  HLT      1  To halt exection of program in order to
                                     enter a different operational mode to
                                     check registers.  Used for trouble-
                                     shooting.  The halt instruction is entered
                                     after your program is entered.  In other
                                     words, you would enter your complete
                                     program, then, using the Roll Mode, you
                                     would enter a halt instruction (FF) in
                                     place of an instruction already
                                     programmed.  After entering the Display
                                     Mode and checking the registers for
                                     errors, you would return to the program
                                     step containing FF, clear it, and
                                     re-enter the program step you had
                                     removed.  (See Continue Mode description
                                     in the Operating Mode Review.)
Go to Subroutine     14NN GTS.NN  2  To instruct microprocessor to branch to a
                                     specified program step (NN) which
                                     contains an operation which you may wish
                                     to use several times in one program. This
                                     instruction set allows you to use the
                                     same operation several times without
                                     having to rewrite it.  The next
                                     sequential step number is saved for
                                     returning from the subroutine.  (See
                                     sample program "Area Problems Using
                                     Subroutine and Return.")  You must have a
                                     "Return from Subroutine" when you have a
                                     "Go to Subroutine."
Return from Subroutine 07 RET     1  To instruct the microprocessor to return
                                     to a specified program step.  This would
                                     be the step immediately following the
                                     instruction set "Go to Subroutine."  (See
                                     sample program "Addition Flash Cards.")
                                     Your must have a "Go to Subroutine" in
                                     order to have a "Return from Subroutine."
                                     [missing word and errors reproduced]
-------------------------------------------------------------------------------

Branching Decision

Branch on Decimal    10NN BDB.NN 2   To instruct the microprocessor to branch
Borrow                               to the specified program step (NN) if the
                                     high order bits of the Accumulator equal
                                     a (9).*
Branch on Decimal    11NN BDC.NN 2   To instruct the microprocessor to branch
Carry                                to the specified program step (NN) if the
                                     high order bits of the Accumulator do not
                                     equal a (0).*
Branch               12NN GTO.NN 2   To instruct the microprocessor to branch
Unconditionally                      to a specified program step (NN).  (See
                                     sample program "Message.")
Branch if Accum.     13NN BRZ.NN 2   To instruct the microprocessor to move to
is 0                                 another program step if conditions are
                                     satisfied.  Most often used in arithmetic
                                     problems.  (See 1 Digit Division.)
Branch if Reg. not  2RNN BVNE.R.NN 2 To instruct microprocessor to branch to a
= Accum.                             specified program step (NN) if Accum. is
                                     not equal to a specified register (R).
                                     (See sample program "Message.")
Branch if Reg. =     3RNN BEQ.R.NN 2 To instruct microprocessor to branch to a
Accum.                               specified program step (NN) if the
                                     contents of the Accum. are equal to the
                                     contents of the specified register (R).
                                     (See sample programs "One Digit
                                     Multiplication" and "Six Letter Guess.")
Branch if Reg. is    4RNN BGT.R.NN 2 To instruct the microprocessor branch to
greater than Accum.                  a specified program step (NN) if the
                                     specified register (R) is greater than
                                     the Accum.
Branch if Reg. is    5RNN BLS.R.NN 2 To instruct the microprocessor to branch
less than Accum.                     to a specified program step (NN) if the
                                     specified register (R) isless than the
                                     Accum. (See sample program "One Digit
                                     Division.")

* The Accumulator contains eight bits of data.  The first four are the high
order bits and the last four are the low order bits.


Program Sheets


Program Name_____________Date_________________Page


Step Hex   Assembler  Byte  Remarks                Register Use
     Code  Code

[There are 22 pages of blank program sheets]


Odyssey2
this gatefold will provide you with an electronic road map - please keep it
open as you work with your Odyssey2 computer


Keyboard

[Illustration of keyboard]


External Flow


[Note: The chart uses colored arrows to indicate Reset and Clear.  I am
labeling those arrows explicitly]

|-----|   |----------------|
|Reset|-->|Command Mode    |<-------------------------------------------------|
|-----|   |                |<------------------------------------------------||
          | C  D     E   P-------------------------------------|             ||
          | |  |     |     |                                   |             ||
          | |  |     |     |<----------------------|           |             ||
          |-|--|-----|-----|<--------------------| |   |-----------------|   ||
            |  |   ^ | ^                         | |   |   Program Mode  |   ||
            |  |   | | |_______________          | ||--|    A        M   |-| ||
            |  |   | |_____________   |          | ||  |Assembler Machine| | ||
        |----  --| |               |  |Reset     | ||  |-----------------| | ||
        |        | |Clear        |--------------|| ||          ^           | ||
|-------------| |--------------| |Execution Mode|| ||          |      ------ ||
|Continue Mode| | Display Mode | |--------------|| ||          |      | -----||
|-------------| |(Step #FF must|                 | ||          |      | |     |
                |be inserted in|    |------------  ||     |----|      | |     |
                |program)      |    |         Clear|v     |           v |Clear|
                |------|-------|    | |--------------|    |  |--------------| |
                       |            | |Assembler Mode|    |  |Hex Input Mode| |
            |--------------------|  | |  I      R    |    |  |    R     I   | |
            |0-9 Display Register|  | |Input  Roll   |    |  |   Roll  Input| |
            |----------|---------|  | |--------------|    |  |--------------| |
                       |            |   |   ^   |       Cl|ear     | ^    |   |
            |----------|---------|  |   |   |   |     |---------|  | |    |   |
            |A-F Display Register|  |   |   |   |---->|Roll Mode|<-| |    |   |
            |----------|---------|  |   |   |         | D    U  |    |    |   |
                       |            |   |   |         |Down  Up |    |    |   |
            |----------|---------|  |----   |         |---------|    |    |   |
            |P Display Program   |  ||    Cl|ear                   Cl|ear v   |
            |       Counter      |  ||  |-----------------------------------| |
            |----------|---------|  |-->|          Input Mode               | |
                       |            ----|Assembler Language Machine Language| |
            |----------|---------| Reset|                                   | |
            |S Display Subroutine|      |------------|-|--------------------|--
            |       Counter      |         ^         v v                ^ Reset
            |----------|---------|         |       |-----|              |
                       |                   |-------|Enter|--------------|
            |----------|----------|                |-----|
            |X Display Accumulator|
            |----------|----------|


Legend
Reset [Yellow block] Clear [Red block]


Computer Symbols

[0] [1] [2] [3] [4] [5] [6] [7] [8] [9] [:] [$] [ ] [?] [L] [P] [+] [W] [E] [R]
00  01  02  03  04  05  06  07  08  09  0A  0B  0C  0D  0E  0F  10  11  12  13

[T] [U] [I] [O] [Q] [S] [D] [F] [G] [H] [J] [K] [A] [Z] [X] [C] [V] [B] [M] [.]
14  15  16  17  18  19  1A  1B  1C  1D  1E  1F  20  21  22  23  24  25  26  27

[-] [Times sign] [Division sign] [=] [Y] [N] [/] [Solid block] [10] [Solid dot]
28  29           2A              2B  2C  2D  2E  2F            30   31

[Man facing right] [Man walking right] [Man walking left] [Man facing left]
32                 33                  34                 35

[Left arrow] [Up arrow] [Filled triangle lower right half]
36           37         38

[Filled triangle lower left half] [Man facing forward] [\] [Submarine] [Plane]
39                                3A                   3B  3C          3D

[Boat]
3E


IB3389-1  AJ9406

ODYSSEY2

THE ULTIMATE COMPUTER VIDEO GAME SYSTEM...BY MAGNAVOX


COMPUTER INTRO!

It's not for everyone - but if you're up to a rewarding mental challenge, here
is a fascinating entry point into a complex and highly technical subject.
This cartridge turns your Odyssey2 into a special kind of computer.  It won't
balance your checkbook or plot the course of a spaceship to Mars - but it will
give you some idea of how those computers do their work.  You will learn how
computers "think."  You will learn how to enter a program - the first step in
learning how to actually write one.  Electronic road maps graphically show you
where each byte of data goes - and what happens to it.  Then, you will
actually run the program and see the exciting results on your TV.  Shut off
the power and the old program is automatically erased so you can enter a new
one immediately!

(C) 1979 Maganvox Consumer Electronics Company  Odyssey is a trademark of the
Magnavox Company.