The TI-99/4A is the first microcomputer with the Plato educational system first by a cartridge based interpreter with disk based lessons and later with a rs232 based Plato terminal program that connected to the main Plato system via modem.
This modem based terminal was never really available to the public so was basically forgotten about in the TI-99 community.
Then in recent years Thomas Cherryhomes set up a Plato environment and has made it a priority to revive the micro computer terminals for many systems. He got ahold of the original terminal software and posted on the Atariage TI-99/4A forum looking for help testing the original terminal software. I downloaded a copy from him and was able to test it connecting to his irata.online Plato server with a wifi modem. There were some incompatibilities with the terminal and irata so Thomas decided to rewrite the terminal in C using the newly created GCC port for TMS9900 development. He was able to get it together but when testing found that the TI-99/4A rs232 port was unable to handle the data rate requirements so he decided to make the terminal use the telnet protocol over the TIPI device designed and built by Matthew Splett. You can download and use this terminal with an expanded 99-4A with 32k RAM expansion and TIPI
Archiver 3.03, often abbreviated as Arc303, is the TI’s equivalent of ZIP files they are compressed files that usually contain more than one other files inside them.
Usually these end with an ‘@’ character to indicate they are archived, although some PC distributions may use a .ARC or .ARK extension instead. To extract the files, you will need a copy of Archiver 3.03 found at http://ftp.whtech.com
https://www.mocagh.org/loadpage.php?getcompany=ai&npp=25&whatsnew=0&start=0&series=TI-99%2F4A+Adventures+Series has a nice list of the games available for this cartridge. You need a cassette player/cable or disk system to load the games with the adventure module. No other expansion is required it works fine on stock console.
By Dan H. Eicher
AVPC - Advanced Video Display Processor, produced by Digit Systems
(Tom Spilane) - This PBOX card use an 9938.
c - Small C by Clint Pulley for the 99/4a.
E/A - Editor Assembler.
FDC - Floppy Disk Controller.
FWEB - Funnel Web.
GRAMULATOR - Graphics Ram Module produced by Cadd Electronics
allows the user to load/modify and run cartridges.
Unlike the GramKracker produced by Millers Graphics
with modifications, this unit could also run MBX
GRAM KRACKER - See Gramulator.
Grand Ram - A ramdisk produced by DataBiotics. Unique in that
it both battery backed up like a Horizon Ramdisk and
provided print spooler software (like the Myarc 512K)
card. It also included connectors on board to connect
to emulate the PBOX bus and cartridge port.
GROM - Graphic ROM
Rom Memory developed by TI that automatically increments.
HFDC - Myarc Hard Floppy Disk Controller.
MBP - Eight port analog to digital card with real time clock.
MBX - Milton Bradley Expansion Unit (yes the toy maker) allowed
the 99/4a to use voice directed games.
PBOX - Peripheral Expansion Box also known as PEB.
PC99 - A software package for MSDOS PC's (486-50 or faster) that
emulate a TI99/4A. This is commercial software and well
PGRAM - Like the GramKracker, but on a PBOX card.
PIO - Parrallel/Printer Port.
POP-CART - Cartridge produced by OPA that up to 512K of grom
code and any number of cartridges could be placed.
SOB - Son Of a Board. This board also plugs into the console,
in the GROM1 socket. It adds an enhanced menu upon power
up and fixes some video initialization problems that are
transparent, unless you are using a 9938 or 9958 video
controller chip in your system.
TIM - TI Image Maker. This is a an 80-column board produced by
OPA. It had a Yamaha 9958 chip and came bundled with the
SOB. It mounts inside the TI console in the TMS9918 socket.
V9t9 - A software package for MSDOS PC's (386-25 or faster) that
emulates a TI99/4A. This is freeware (produced by Ed.
Swartz) and no support from the author is available,
but the source code is.
XB - Extended Basic.
Power supply from a 99/4 (NOTE: NOT COMPATIBLE WITH 4/A)
Power supply from a 99/4A
Power supply from a 99/4A QI
This is the connector on the back of the console that the ac adapter plugs into. Some of these connectors have 4 pins, while others have 3. The newer power supplies (QI) only have 2 pins. They way they were set up you can use any ac adapter with any of the consoles.
The AC voltages in are:
1. Black 8 volt
2. White 16 volt
3. Red 5 volt
4. No connection
The power supply is a very standard setup, and could be replaced by any standard PC power supply.
The DC voltages out are:
Pin 1 = -5 volt
Pin 2 = +12 volt
Pin 3 = GND
Pin 4 = +5 volt.
No AC Voltage? check the fuse!
TI was required by the UL to add a fuse to the external power supply. Their solution? add a pigtail to the power cord with the fuse in a little plastic box.
These fuses tend to blow after so many years of use, so the fuse needs to be replaced or just remove the pigtail if you are using a power strip with built in circuit breaker making the fuse unnecessary. You will find it’s just stuck on the old plug with some adhesive and it should come apart with some effort.
Fuse type: 4/10A 250V
Schematic for power supply (not QI)
Here is an interesting project replacing the console power supplies with a new board:
The Extended Basic module was not included with the console and was semi-expensive originally.
Extended Basic exists in two distinct versions, Version 100 and Version 110. To determine which you have us this small program:
10 CALL VERSION(A) :: PRINT A
Only a very small handful of the earlier Vn 100 were sold.
Principal difference is speed: Version 110 is much faster.
Version 110 fixes bugs and supports sprites and features on the 4A that were not available on the 99/4
EXTENDED BASIC is a much larger language than TI Basic.
The increase in operation speed is not shown by magazine ‘bench tests’ which use very short specific programs. In a typical program you will find the program runs in about 30% less time. Line transfers and screen handling are particularly faster than in TI Basic. This is due to the fact that some of these routines are in assembly language in Extended Basic while TI BASIC is 100% GPL.
Extended Basic also adds any new commands and functions over TI BASIC enabling better use to be made of limited memory, and also permitting friendlier programs to be written.
Extended Basic allows for multiple commands per program line using :: as a command delimiter
Extended Basic supports the 32k memory expansion allowing 24k to be used for program data, the rest of the memory is used for stack.
Many TI BASIC programs can be loaded in Extended Basic, and will then run faster.
TI Basic programs over 12k cannot be loaded due to lack of memory. (memory expansion doesn’t help with this due to TI BASIC programs load into VDP ram only)
Some TI Basic programs will load but cannot RUN due to lack of memory.
TI Basic has two extra character sets: if these are used, they will produce a BAD VALUE error in Extended Basic. Extended Basic uses the memory saved by dropping these sets (15 and 16) to produce the Sprites
The most feature rich terminal program for the 4/a is TELCO.. This supports ANSI graphics (NO COLOR) and 40 and 80 column modes (80 column requires a 9938 or greater VDP and does not work currently with F18a 80 column mode) Multiple file transfer protocols, printer spooling etc..
Term80 – 80 column terminal on stock VDP, uses a TINY FONT but supports color ANSI and high baudrates using specialized rs232 routines and memory devices for buffering data.. buggy and incomplete but still pretty cool
MXT – Mass Transfer – allows for multiple file transfers and standard ascii terminal emulation , xmodem included as well this has also been ported to work as a telnet client for TIPI
Fast Term – ASCII terminal program that works up to about 19200 baud..
Terminal Emulator and Terminal Emulator II – cartridge based terminals support 110 and 300 baud, 7 bits even parity and has a proprietary terminal emulation mode allowing for graphics and sound, also only supports file transfers from TE compatible systems (TIBBS FOR INSTANCE)