ftp.whtech.com/ftp.whtech.com.tar/ftp.whtech.com/articles/archives/limanews.exe/99_4.TXT

Text File | 2006-10-19 | 15KB | 282 lines

ORIGINALLY PUBLISHED IN LIMA NEWSLETTER FEBRUARY 1991

     ^^^^^^^^^^^^ THE 99/4 HOME COMPUTER
     ^^^^^description of an antique by Charles Good
     ^^^^^^^^^^^^^^Lima Ohio User Group

     A SHORT HISTORY OF THE TI HOME COMPUTER
     TI began shipping the 99/4 (copyright 1979 on the color
bar title screen) in October 1979.  It cost $1150 bundled
with a 13 inch color monitor (FORTUNE, December 3, 1979,
p.54).  Initially you had to take the monitor and could not
purchase the 99/4 separately, and most purchasers had to pay
close to full price.  Bundling was necessary because the
99/4 console passed but TIs TV modulator initially failed to
pass FCC lab tests for noninterference with radio and TV
broadcast reception.  The modulator emitted too much RF
radiation (BUSINESS WEEK, March 19, 1979, p.37).  However,
at that time the FCC did not regulate RF radiation from
computing devices not hooked directly to TVs.  So TI got
around the FCC regulations by offering to the public a
"complete package".  It wasn't until January 1, 1981 that
the FCC began testing ALL computers likely to be used in a
home environment for TV/radio broadcast interference
(POPULAR COMPUTING, November 1981, p.6).  TI eventually came
up with a TV mudulator that would pass FCC tests and on
November 28, 1980 began selling the console and monitor
separately.  The console's list price was $650 (BUSINESS
WEEK, December 8, 1980, p.28).  This was in one respect was
actually a price increase, because the separate prices of
the console and monitor were $250 more than their previous
bundled price.

     TI never published any sales data for the 99/4, but an
independent market research firm estimated that TI would
sell 25000 between its introduction and the end of 1980
(FORTUNE, June 16, 1980, p.139).  During the summer of 1981
TI quietly introduced the 99/4A with a list price of $525.
By the time production of the 99/4A ceased in late 1983 or
early 1984 the store price for a brand new 99/4A was $50,
and over 1 million, perhaps several million 99/4As had been
sold.

     SUMMARY OF DIFFERENCES BETWEEN THE 99/4 AND 99/4A.
     The most obvious differences are the keyboard, the lack
of lower case letters on the "4", and the "4"s EQUATION
CALCULATOR.  Most "4"s have an earphone jack on the front
for private listening, but mine doesn't.  I will discuss
most of these obvious differences in detail.  Other
differences are listed in an accompanying article by Mike
Wright.  The 4A gets its "A" from the fact that it has a
9918A video processor, whereas the 99/4 has a 9918 video
processor.  The 9918A has bit map mode, which is not found
on the 9918 processor.  This means that any software that
uses bit map mode will not run on the 99/4.  Other
differences between the 99/4 and 99/4A (such as the "4"s
lack of an XOP assembly directive) are referenced in the
index of the Editor/Assembler manual (p.456) under the
heading "Computer differences".

     In general, all software written for the "4" will run
on the 4A.  Some complicated routines on the 4A were
required to achieve this compatibility.  The "4" has 256
bytes more free memory in TI BASIC than the 4A, so some
BASIC software written on a "4" may not work on an
unexpanded 4A.  Lots of assembly or GPL software written for
the 4A will NOT work on the "4", and there is no easy way to
upgrade a "4" to a 4A.  The Mini Memory module and its line
by line assembler, and the E/A module and its editor and
assembler work OK on the "4".  A partial list of "won't work
on the 99/4" software includes TI-Writer, Multiplan,
Funnelweb v4.x, the LINES program that comes with the Mini
Memory module, all the Milton Bradley game modules that were
created to accompany the MBX system, Word Invasion, Parsec,
Story Machine, Alpiner, Dragon Mix, and Word Radar.  Most of
these modules and the LINES program are probably
incompatible because they use bit map mode.  There are
probably other reasons for the incompatibility of Multiplan,
TI-Writer, and Funnelweb.  Even the non-editor parts of
Funnelweb won't work on the "4".  When you boot Funnelweb
into the "4" using the extended basic module, the title
screen shows blanks where there should be lower case
letters.  You can then go to Funnelweb's extended basic user
list, but here the "4" locks up.  You can't boot any
software from the XB user list.

     THE KLUDGY 99/4 KEYBOARD
     After playing around with my "4" for a couple of
months, I am forced to agree with the statement made in an
accompanying FORTUNE magazine article.  The 99/4 is a real
dog, mainly because of its keyboard.

     There are 41 "chicklet" style keys, each slightly
contoured and shaped like a narrow rectangle.  The 4A
keyboard has 48 keys.  Although each 99/4 key depresses
separately, the keys are not what experienced users would
call "full travel" There is no tactile response, no click,
before the keys suddenly bottom out at the end of their
downward travel.  Non-alphanumeric keys include one (and
only one) SHIFT, an ENTER, a SPACE bar, and a SPACE key
immediately to the left of the "A" key.  Alpha keys always
produce upper case letters, so the SHIFT key is not used as
often as it is on the 99/4A.  There is are no ALPHA LOCK,
FCTN, or CTRL keys on the "4".  The "4"s SPACE key and bar
do exactly the same thing, leave a blank space.  I can see
no reason at all for this space KEY, in addition to the
normally positioned space bar.  There are ASCII characters
built into the 99/4 console that are not implemented on its
limited keyboard, yet there is this stupid extra space key.

     Touch typing on the 99/4 is difficult.  The keys are
spread apart the same distance as on the familiar 99/4A
keyboard, so it is possible to get all your fingers at once
onto the keys.  But the small vertical size of the keys and
their lack of tactile feel makes touch typing difficult.
The small size and minimal contour of the "4"s keys makes it
difficult for a touch typist to find by feel and seat his or
her fingers in the center of the desired keys as the fingers
move blindly around the keyboard.  The fully contoured much
larger keys of the 4A (larger because there is less space
between keys) makes touch typing much easier.  A special
problem to experienced touch typists is the lack of any key
to the right of the "L".  This means there is no "home" key
for the little finger of the right hand to touch, and this
will drive most touch typists crazy.  Frequently, when I try
to type on my "4" I end up accidently moving my fingers over
one key to the left on the home key row so that all ten
fingers have something to touch.  My left hand pinky finger
is then on the useless SPACE key instead of on the "A" where
it should be.  Then I type rtow fevfw.  TI recognized this
problem.  The only application software written for the 99/A
that is likely to require touch typing, the Terminal
Emulator II, has a keyboard overlay with a raised area
creating a fake key for the right hand's little finger.

     TI provided a series of overlays specifically for use
with the 99/4 and not usable with the 4A.  Some overlays
were packaged with the "4" and others were available with
specific command modules.  Because of the narrow vertical
size of each key there is enough room between rows of keys
on the "4" to display a text prompt immediately above ANY
key, not just above the numeric keys as is the case with the
4A.  The overlays have text prompts for special keypresses,
and cover the entire "4" keyboard, with the keys sticking up
through holes in the overlay.  Special keypress usually
involve using the SHIFT key in combination with a letter
key.  One overlay packaged with the "4" shows the editing
keys used in BASIC.  SHIFT/Q=quit.  SHIFT/W=begin.
SHIFT/ESDX= arrows. SHIFT/R=redo.  SHIFT/T=erase.
SHIFT/A=aid.  SHIFT/F=delete.  SHIFT/G=insert.
SHIFT/Z=back.  SHIFT/C=clear.  SHIFT/V=proceed.  There is
nothing intuitive about some of these keypresses (why not
SHIFT/B instead of /Z for back), so the overlay is really
needed.  Another overlay packaged with the "4" shows the
split keyboard keys that can be used with some games to
simulate the 8 positions of joysticks #1 and #2.  In
addition to the overlays packaged with the computer, I have
seen overlays designed for use with the following command
modules: Terminal emulator I, Terminal emulator II, Video
graphs (PHM3005), and Video Chess.  There may be other
overlays I havn't seen.

     One of the reasons I give the 99/4 my "real dog" rating
is the uncontrollable multiple repeat of the keys on my "4"s
keyboard.  This makes it almost impossible to do any useful
typing, touch or hunt and peck, on my "4".  Autorepeat of
all keys at rate of 12 characters per second after a 1
second delay is listed as a NEW feature of the 99/4A (99ER
MAGAZINE, Vol 1 #2, July/August 1981, p.48).  Autorepeat is
NOT described in TI literature as a feature of the "4".  On
my "4" any of the keys are likely to repeat INSTANTLY.  When
you depress a "4" key, the keypress registers in the memory
of the computer at a point about 1/2 way down the travel of
the key.  There is no tactile response that this has
occured.  The only thing your finger feels during a keypress
is the sudden stop when the key bottoms out.  If the key
hovers in this "1/2 way down" region you get mmmultiiiplle
displays of theee keeey on the scrrreennn.  Try as I might,
I can't seem to avoid this.  My "4"s keyboard is very
sensitive.  Other experienced 4A users who have tried my "4"
all have the same problem.  Having to use backspace
(SHIFT/S) and delete (SHIFT/F) after every 6-10 keystrokes
gets old really fast.  It has been suggested to me that this
problem may be related to the ageing of my "4".  The
condition may not have existed when my "4" was built.  One
collector of TI computer products told me, "I had a 99/4
that did that.  I got rid of it and replaced it with a 99/4
that still works fine."

     ONLY UPPER CASE LETTERS
     No keypress on the "4" keyboard will give ASCII codes
97-122, the lower case letters.  Everything you type is in
upper case, and this means you only use the SHIFT key in
routine typing to shift the numeric keys and display
!@@#$%^&&*().   The 99/4 uses a 5x6 pixel grid to display
upper case letters.  The 99/4A uses a 5x7 grid to display
both upper case and lower case text.  If you load into the
"4" BASIC software written on a 4A that includes lower case
text, the program seems to work OK, but no lowercase letters
are displayed on screen.

     THE EQUATION CALCULATOR
     When you PRESS ANY KEY TO CONTINUE from the color bar
powerup screen of the "4", you get a menu with three
choices.  Press 1 for TI BASIC, 2 for EQUATION CALCULATOR, 3
for TITLE OF COMMAND MODULE.

     The EQUATION CALCULATOR is a way of using the "4" in
mathematical calculations without having to write a BASIC
program to do the calculations.  You can do simple
arithmetic, and you can also use exponential numbers, PI,
SQR, exponents, SIN, COS, TAN, and ATN in your calculations.
Everything that can be done using EQUIATION CALCULATOR can
also be done using a TI BASIC program, or directly from
BASIC command mode.

     The EQUATION CALCULATOR screen is divided into three
sections.  The bottom section is where you do your
calculating.  You can, for example, type in a simple
calculation such as 1567+56.98-145+(12/98), press <enter>,
and display the answer.  To do the same thing in BASIC
command mode, you would have to type PRINT before you typed
the numbers of the calculation.  A single calculation is
limited to 28 characters (one line of text).

     You can define variables such as LENGTH=60, press the
up arrow, and have this variable stored in memory and
permanently displayed in the upper third of the EQUATION
CALCULATOR screen.  You can display up to 6 variable names
and their current values on screen in this way and not have
to worry about the display scrolling off the top of the
screen.  You can do the same thing in BASIC command mode by
pressing <enter> after typing LENGTH=60.  The value of
LENGTH would be stored in the computer's memory, but it
would only remain on screen until it scrolled off the top
due to subsequent entrys.

     You can also define an equation such as
PERIMETER=2*LENGTH+2*WIDTH and store this equation in the
middle part of the EQUATION CALCULATOR screen.  You can then
define the values of the variables LENGTH and WIDTH, use the
down arrow to bring the equation into the bottom work area
of the EQUATION CALCULATOR screen, press <enter> and display
the current value of PERIMETER.  You can then redefine
LENGTH and/or WIDTH, and reuse the equation to calculate the
new value of PERIMETER.  You can also store equations for
repeated use in a BASIC program, although you cannot store
such an equation in memory in BASIC command mode.  In
command mode you would have to retype the equation each
time.

     I don't think EQUATION CALCULATOR is very useful.
Apparently TI didn't either, because they dropped it when
the 4A was released.  From BASIC (a program or from command
mode) you can do all the same things, and more.  The main
limitation of EQUATION CALCULATOR is the 28 character size
of a formula or chain calculation.  The most common routine
calculating I do on my 99/4A is to balance my checkbook.  I
enter BASIC command mode and type PRINT, followed by my
initial bank balance, followed by all my subsequent
withdrawals (as minus numbers) and deposits (as positive
numbers).  Before I press <enter> to display my balance I
can check the screen to see that all the numbers in the
calculation are typed correctly and use INSERT or DELETE to
correct mistakes.  Such a long chain calculation requires
several lines on the screen to display all the digits before
pressing <enter>.  TI BASIC command mode gives me 4 lines.
EXTENDED BASIC command mode gives me 5 lines.  EQUATION
CALCULATOR allows me only one line of digits.

     CONCLUDING REMARKS
     When it was released in 1979 the 99/4 was the only
consumer device that could really be called a "Home
Computer".  It was the first to utilize cartridge software.
Its speech synthesis was, and still is, unequaled.  It was
easy to use, easy to program in BASIC, and it was powerful.
Its high price was probably the major reason for its
initially limited sales.  Its rotten keyboard didn't help
either.   I'm sure glad we now have the 99/4A.  The 4A is
much superior to the "4".
     .PL 1