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ORIGINALLY PUBLISHED IN LIMA NEWSLETTER MARCH 1989

      MY EXPERIENCES WITH THE DIJIT SYSTEMS AVPC CARD
     ^^^^^^^^^^^^^^^^^by Charles Good
     ^^^^^^^^^^^^^^Lima Ohio User Group

      INTRODUCTION:
     Lets be honest with ourselves.  Probably the biggest
single technical limitation of the TI99/4A, besides limited
CPU memory, is its lack of an 80 column text display.  With
only 256 pixels of screen width to play with, there is
absolutely no way you can get 80 columns.  Each letter would
be only 3 pixels wide with no space between letters! Perhaps
some of you have seen the 64 column TI Forth editor or the
64 column DV80 text scroll program that is in many user
group libraries.  These 64 column displays are just awful.

    Yes, I know you can simulate 80 columns with left/right
windowing as in the TI-Writer or Funnelweb text editors.
But actually reading an 80 column page on the 99/4A's 40
column screen with these text editors is a big pain.  You
have to keep pushing FCTN/5 as you scan left/right on each
line, and it is sometimes hard to move your eyes from the
end of one line (right margin) to the beginning of the next
line (left margin).  You can also view 80 column text on the
99/4A's 40 column screen without windowing by using T(ype)
with DM1000 or V(iew) with DSKU or the Funnelweb 40 column
editor, but the resulting text display on the screen is less
than satisfactory.  Each actual text line wraps on the
screen to become two screen lines.  You do not get a "what
you see is what you get" (WYSIWIG) display and words get cut
into two parts at the point of line wrap.

     The lack of an 80 column display with the 99/4A is a
major reason cited by previous TI users who have sold their
TI systems and purchased IBM clones for home use.  This is
based on conversations I have had with several ex-TI users,
including two past TI user group presidents, who have
abandoned the TI for IBM land.  Hardware and software that
permit an 80 column text display is really needed to make
our 99/4As technically comparable to the competition and to
maintain user interest.

      THE 80 COLUMN CHOICES:
     Currently there are only two hardware choices if you
want to upgrade your TI to 80 columns, the Myarc Geneve
computer-on-a-card or the DIJIT Systems AVPC card, both of
which use the TI PE box.  Both use exactly the same video
chip and  thus both have exactly the same capability to
produce 80 column text using a screen width of 512 pixels.
You can also display up to 512 colors at a time, if you have
the right color monitor.  This color diaplay is said to be
comparable to or better than the display of any other
currently available personal computer.

     The Geneve currently costs about $500-$520 new and
gives you a nice 101 key keyboard and lots of CPU memory.
There is, however, very little software that takes advantage
of all this CPU memory.  Most of the commercial and PD
software available for the Geneve is also designed to run on
the 99/4A and thus doesn't use vast quantities of memory.
Based upon conversations with Geneve owners present at the
Nov 88 Chicago faire, the answer to the question "What can
your Geneve do that the 99/4A can't do?" is usually "Not
much other than 80 columns and better graphics." These same
Geneve users also complained about what their computers
would NOT do.  This and that software which runs fine on the
99/4A has problems when run on a Geneve.  I suspect that the
full potential of the Geneve, with all its CPU memory, may
never be utilized.  Because of the small user base
(estimated in exchange newsletters to be much less than
2000), there is no financial incentive for the few existing
TI assembly language programmers to write really massive
programs that utilize the Geneve's large CPU memroy.  Such
software would be too big to work from a 99/4A.

     The main subject of this review article, the DIJIT AVPC
(advanced video processor card), costs $220.  To date,
discounts are not available.  Functionally it appears to me
to be the equivalent of the Geneve without the fancy
keyboard and without the extra CPU memory.  With tha AVPC
and a 99/4A system you can run some of the software that is
designed specifically for the Geneve in GPL mode.  The AVPC
is the only currently available alternative to the Geneve
for 80 column work using a system built around the TI
peripheral expansion box.

     Until recently a third choice existed for 80 column
work.  Mechatronic, of West Germany, manufactured a circuit
board that pluged into the side expansion port of the 99/4A
console and used the same video chip as the Geneve and the
AVPC.  This product is, however, no longer available.  On
Feb 15, 1989 I gave TAPE Ltd of Ontario CA a telephone call
and talked to the owner Franz Wagenbach.  TAPE is the only
North American importer of Mechatronic products.  Mr.
Wagenbach told me that he is completely sold out of all
Mechatronics hardware, and with the exception of the TI
mouse he does not expect Mechatronics to manufacture any
more TI hardware products in the future.  Mr.^Wagenbach did
say, however, that if he had in hand 100 prepaid orders he
beleived he could convince Mechatronics to resume production
of its 80 column peripheral.  Uh huh! Don't hold your breath
waiting for this to happen.  TAPE's phone number is
714-989-9906.  Mr.^Wagenbach stated that he DOES intend to
stay in the TI market and offers products not available from
other sources, including Mechnatronic XBII Plus (a module I
think), the 99/4A intern book, and the TI Mouse (used
instead of a joystick from the joystick port).

      AN OVERVIEW OF THE AVPC CARD:
     As currently sold the $220 AVPC card comes with 128K of
VDP RAM governed by the Yamaha V9938 video chip.  The AVPC
card requires the use of a composite monochrome 80 column
monitor ($75-100) or an Amiga compatible RGB analog color
monitor ($275-$500).  See the discussion of monitors
elsewhere in this newsletter.  YOU CANNOT USE A TV OR A
COMPOSITE COLOR MONITOR OR A TTL MONITOR WITH THE AVPC CARD
FOR 80 COLUMN WORK.  There are sockets on the AVPC card for
an additional 64K of VDP RAM which can be directly accessed
by the V9938.  However, to date no software has been written
to take advantage of this extra 64K, so to keep costs down
the AVPC leaves this memory for future expansion.  The
Geneve also has 128K of VDP RAM and the V9938 chip, but with
the Geneve there is no provision for adding the additional
64K.  You plug the card into any empty slot in the PE box
and make a slight modification to your console, as described
below.  A DIN 6 video port and a 9 pin DB-9 light pen/mouse
port are at the back of the card and stick out the back of
the PE box.  You run a cable directly from the video port of
the AVPC to the monitor video input.  For sound, you need a
separate cable between the console and the monitor audio
input.  You have to make these cables or have your dealer
make them for you.  They are easy to make using the "typical
monitor connections" section of the AVPC docs and parts from
Radio Shack.

      NECESSARY CONSOLE MODIFICATION:
    "What?  Modify the console!  Not me," you may be saying.
I understand the fear many have of taking your favorite
computer apart.  Believe me, you can do it.  No soldering is
required, and the job is only a little more complex than
taking the console apart to clean out the cartridge port.
The documentation that came with my AVPC is labeled
"Preliminary Copy" and contains excellent step by step
written directions and detailed diagrams relating to the
console modification.   Working very slowly while carefully
reading the instructions the console modification took me
about 1 hour from start to finish.  If the job had been at
all difficult I wouldn't have attempted the modification.
DIJIT SYSTEMS will do the work for you for $25. if you ship
them your console.

     After completely disassembling the console and exposing
the mother board the first thing you do is sever one of the
printed traces on the circuit board.  You need a good hand
lens and an xacto knife for this job.  I used a 10X
microscope eyepiece removed from the microscope and turned
upside down for my hand lens.  You use the hand lens to make
sure that absolutely no metal remains at the point where you
are severing the trace.  You then remove the console's VDP
chip from its socket, bend out one of the pins, hook a
wiring harness to some of the chip's pins, and reinsert the
chip in its socket.  The wiring harness has very tiny
insulated spring loaded clip hooks resembling the sort of
clip hook one finds on the end of a dog leash.  I have seen
these tiny insulated clips at several area Radio Shack
stores.  The use of these clip hooks eliminates the need for
soldering, and they are quite reliable according to the AVPC
documentation.

      WHAT CAN YOUR COMPUTER DO WITH THE AVPC?
     In my opinion 80 column word processing is the most
important useful application of the AVPC.  The card comes
with a public domain 80 column version of TI-Writer and is
also distributed with Funnelweb v4.13 in 80 columns.
Charles Earl told me at the Nov 88 Chicago faire that PRESS
will work in 80 columns with the AVPC (if and whan PRESS is
ever released).

     I am writing this article using 80 column Funnelweb
v4.13.  I can't imagine ever wanting to go back to a 40
column text editor.  I really like the 80 column Funnelweb!
One of the nice features is the ease with which you can
V(iew) a file that is listed in the ShowDirectory display.
You don't have to load the whole file into memory to V(iew)
it, and this is nice because loading a large file into
memory can seem very time consuming.  Just mark one of the
20 displayed files and (if it is a DV80 or DF80 file) press
V.  The first screen full of text from the marked file
appears in 80 columns.  The first and last file line numbers
of the screen display are also indicated.  If you want to
look at the next screen full of text from the file press any
key.  If you want to abort viewing the file, press BACK and
you are returned to the ShowDirectory display.  From there
you can view another file.  If you want to check the
contents of another disk while the ShowDirectory is on the
screen, just insert the disk, press REDO, and the new disk
directory appears on the screen.  All of these features of
Funnelweb's 80 column ShowDirectory make it real easy to
quickly scan a disk full of text files, such as Central
Westchester's "newsletter on a disk", and then read specific
files on the screen.

     Another thing you get with the AVPC is the ability to
display high resolution graphics in up to 512 colors.  The
card comes with a utility that allows you to view any
graphic that is in MYART format.   You need a Geneve to
create new pictures with MYART or to convert other graphic
fomats over to MYART format.  Once these graphics have been
created, however, they can be viewed using a 99/4A system
that includes the AVPC card.  The results are sometimes
spectacular.  Several nice MYART pictures are included on
disk with the AVPC.

     A number of graphics demonstration programs and fractal
programs originally written on the Geneve work just fine
with the AVPC.  Some of these are distributed with the AVPC
and others are available from the DIJIT Systems BBS.  These
"gee whiz" demos are fun to look at but don't do anything
really useful.

     In the area of Terminal Emulation software, there is an
experimental version of Fast Term that works, with a few
bugs, in 80 columns on the AVPC.  TELCO versions greater
than 2.0 use the extra VDP memory of the AVPC as a sort of
RAM disk to store TELCO modules.  Using the AVPC, TELCO
executes much faster than it does using a 99/4A without an
AVPC card.

     I understand that there is a MULTIPLAN patch available
that allows the AVPC to display MULTIPLAN in 80 columns.  I
don't have this software yet.

     You are supposed to be able to use mice and trackballs
with the AVPC, but I am not sure for what.  There is a
"mouse/light pen port" on the AVPC. Assembly language mouse
routines have been written for mouse use in assembly
language software and from XBASIC.  DIJIT systems provides
these mouse routines as well as detailed instructions on how
to make cables to properly hook just about any of the
currently marketed mice to the AVPC.  To date, no software
that actually does anything has been written to take
advantage of these mice.

     As this article is being written, DIJIT Systems is
demonstrating a video digitizer (the DIJIT-EYE-ZER) at the
Feb 89 TI FEST WEST.  This device is said to include
Gemlocking and "real time frame grabbing".  It is a
peripheral that attaches to the AVPC card.  The digitizer
will be able to create a computer image in 1/25 of a second
of anything seen by a video camera, a video tape, or off the
air and seen by a TV.  I have no information on price or
other specifications.  This sounds like a very serious, and
expensive, piece of equipment.

     Software not specifically written for the AVPC runs
normally in 28, 32, or 40 columns just as it would without
the AVPC.  Because you are using a better monitor with
better resulution the screen display with this software is
much sharper.  You can easily see every individual pixel of
the 256 pixel wide normal screen display.

      WHAT YOUR COMPUTER CANNOT DO WITH THE AVPC CARD:
     It seems that whenever a new peripheral comes out it
turns out that this or that softrware won't work with the
new peripheral.  This is true for the AVPC, although I
suspect that the list of 99/4A software that won't work with
the AVPC is much smaller than the list of 99/4A software
that won't work with the Geneve.

     Any terminal emulator software that uses interrupts
will have problems with the AVPC.  TELCO works ok, most of
th others don't.  The problem is with the ROM based software
that is part of the various RS232 cards.  DIJIT has solved
this problem by selling EPROMS for the TI, CorComp, and
Myarc RS232 cards that make these cards fully compatible
with the AVPC.

     Most versions of the Horizon Ramdisk software based
ramdisk operating system (ROS) are partially incompatible
with the AVPC.  The problem shows up in software that is
designed to use 80 columns of text.  With FUNNELWEB for
example, you can boot the 80 column FWB editor from a
Horizon just fine, and you can without difficulty exit the
80 column editor and go back to other parts of FWB that are
stored on a Horizon.  However from within the 80 column FWB
editor you can only load or save text files with LF and SF
to and from  a floppy.  You can't LF and SF to and from a
Horizon if you use FWB's 80 column editor or the public
domain 80 column version of TI Writer that comes with the
AVPC.  Using the FWB 40 column editor causes no problems
with LF or SF in 99/4A systems equipped with an AVPC.  The
solution is simple.  Load a corrected ROS into the Horizon's
RAM.  Such an ROS is available from Bud Mills Services
(manufacturer of the Horizon and owner of the Horizon ROS
copyright) and from DIJIT.  This special ROS makes the
Horizon fully compatible with the AVPC.  Unfortunately, the
ROM based Horizon operating system sold by Genial
Computerware cannot be corrected, because it is in ROM.  The
AVPV card is not compatible in 80 column mode with Geneal
Computerware's Horizon EPROM operating system, which
exhibits the problems with LF and SF described above.

     The following 99/4A software is known by me not to work
properly on systems equipped with an AVPC card.  There is
probably other incompatible software that I don't know
about.
     ---BOOT v4, by John Johnson, will not boot programs
from its menu.  You can, however, bring up a disk directory
with BOOT, mark a program, and then boot the marked program
from LOAD A PROGRAM.
     ---EZ-KEYS PLUS appears to load properly, and the
macros appear to work.  However, if you load (or type in)
XBASIC code after loading EZ-KEYS PLUS, the XBASIC code will
not work properly.  On systems equipped with an AVPC,
EZ-KEYS PLUS does not properly print out 28 column lists of
XBASIC code with checksums added.
     ---QUCIK RUN doesn't work at all.  XBASIC programs that
have been modified on another 99/4A computer to run quicker
won't run at all on systems that have an AVPC.

     MANUFACTURER SUPPORT FOR THE AVPC CARD:
    DIJIT systems has a free BBS to support its products.
The BBS is available to anyone, not just registered AVPC
owners, and the only cost is your telephone charge.  The BBS
contains text files, software, and MYART picture files in
its download section.  This BBS was the first in the country
to have Funnelweb v4.13 in 80 columns available for
download.  Any new software that is found to be compatible
with the AVPC is put on the BBS.  There is also an upload
section and an E mail section that allows you to leave and
receive messages for DIJIT's owner Tom Spillane.

     You can also talk to DIJIT over the phone using plain
old fashoned voice communication.  I have DIJIT's voice line
a call and almost immediately the phone was answered by Tom
Spillane, DIJIT's owner.  Tom gave me direct answers to some
questions I had about the AVPC, and provided some of the
information used in this article.  I really appreciate this
kind of manufacturer support.

     The AVPC is apparently a completely open system.
Unlike Myarc, which is keeping to itself important
information about its Geneve computer, DIJIT will provide
any and all technical information about the AVPC to anyone
who asks.  In its promotional literature DIJIT mentions a
"programming package" that they will send out to those who
wish to try their hand at programming for the AVPC.
Personal communications I have had with Tony McGovern
(author of FUNNELWEB) and Charles Earl (author of TELCO and
PRESS) indicate that DIJIT Systems has been very generous in
providing all needed technical details about the AVPC for
programming purposes.  To date, DIJIT has not marketed any
of its own software and has relied on others to write
software for the AVPC.  If DIJIT does stay out of the
software marketing business there is no reason for DIJIT to
keep any details of its hardware a secret.  DIJIT apparently
does not want to make the same mistakes that TI made when TI
tried to corner the market for 99/4A software.

      THE FUTURE OF THE AVPC CARD:
     The AVPC is like the Geneve in that it is a piece of
hardware in need of really good assembly language software.
There are relatively few really good assembly programmers
left in the TI community.   Besides the software already
available, there is the definite promise of Charles Earl
that PRESS will work with the AVPC in 80 columns, and a
vague suggestion by Tony McGovern (in the doc file that
accompanies the 80 column Funnelweb editor) that he may do
further programming specifically designed for the AVPC.
DIJIT's "open system" policy may very well encourage other
software programmers to create software for the AVPC.
Nevertheless, I think it would be unwise for 99/4A users
thinking of "upgrading" to purchase the AVPC and wait for
desired software to appear later.  There are disappointed
Geneve owners who are still waiting for software.  Take a
look at the software and hardware peripherals described
above that are currently available for use with the AVPC and
make a purchase decision accordingly.  Don't assume that any
fantastic new stuff will come along in the future.  Maybe it
will and maybe it won't.  If you don't like what is
available now, wait for the future to arrive if it ever
does.  Personally I find the ability to do word processing
in 80 columns with high quality software (Funnelweb, maybe
later PRESS) fully justifies the $220 I paid for my AVPC.
My AVPC will help maintain my interest in my 99/4A system
and postpone, perhaps indefinately, the need to "upgrade" to
an IBM clone system.

      DIJIT Systems
     ^3540 Adams Avenue Suite B
     ^San Diego CA 92116
     ^Voice phone [phone] or 619-295-3301
     ^BBS phone [phone]
     .PL 1