Click Here to visit our Sponsor
The History of Computing The Magazine Have Fun there ! Buy goodies to support us
  Mistake ? You have mr info ? Click here !Add Info     Search     Click here use the advanced search engine
Browse console museumBrowse pong museum


Ready prompt T-shirts!

see details
ZX81 T-shirts!

see details
ZX Spectrum T-shirts!

see details
Spiral program T-shirts!

see details
Atari joystick T-shirts!

see details
Arcade cherry T-shirts!

see details
Battle Zone T-shirts!

see details
Vectrex ship T-shirts!

see details
Atari ST bombs T-shirts!

see details
Competition Pro Joystick T-shirts!

see details
C64 maze generator T-shirts!

see details
Moon Lander T-shirts!

see details
Elite spaceship t-shirt T-shirts!

see details
Pak Pak Monster T-shirts!

see details
BASIC code T-shirts!

see details
Vector ship T-shirts!

see details
Pixel adventure T-shirts!

see details
Breakout T-shirts!

see details


Texas Instruments
TI 99 / 4A Beige

Interesting information from Gregg Eshelman:
There were two versions of the beige TI 99/4A. They look virtually identical but the final revision was known inside TI as the "QI" or Quality Improved. The QI is the only version with the unlicensed ROM cartridge (Command Module in TI-speak) lockout. Various hacks were created to cure this. The simplest being a device that plugged into the side expansion connector.

A most useful addition was a three slot device that plugged into the Command Module slot and allowed three cartridges to be plugged in and selected via a slide switch. It also included a reset button. The original version was a bare board with a prop under the end then later a full plastic cased version was made.

Yet another cartridge slot "peripheral" was a 3rd party cartridge that included the functions of the Mini Memory (with 32K of battery backed RAM instead of 4K) the Editor/Assembler, an enhanced TI Extended BASIC with even more functions, a Disk Manager that supported double density floppies if the system had a double density disk controller, and some other stuff I can't recall.

TI never produced a disk controller that supported double density floppies, but late in the system's life TI produced a new version of the Disk Manager cartridge that supported Double Density with 3rd party controllers. This is a very rare cartridge and was much sought after. However there were 3rd party programs on disk that would work with any disk controller but they required a memory expansion upgrade. (Still didn't allow double density with the TI disk controller.) The TI disk controller manual, on connecting external drives via the card edge connector, had this line in it. "You can break off this tab, then you can throw away the card." A funny admonition to be careful, but I wonder if anyone going really careful, step by step with the manual ever broke the tab off. :)

The reason why the PEB looked like it was built to military grade specifications and all TI and some 3rd party expansion cards had die cast "clamshell" enclosures was due to the FCC insisting that computers of the day produce practically zero detectable EMI/RFI interference. This drove the cost up an extreme amount which didn't help sales of the PEB.

Many companies produced memory, disk drive and other expansion peripherals that plugged directly into the side of the console. The last and most compact developments bundled memory expansion, DS/DD disk controller, a connector for the Speech Module's circuit board and other upgrades into a package barely larger than the TI Speech Module. There were many 3rd party upgrades for the Peripheral Expansion Box or PEB. Among these were 48/128/256K memory expansions, an 80 Column video card, a CP/M card which could be used in conjunction with the 80 column card and the ultimate PEB upgrade, the Myarc Geneve 9640.

Both the Geneve and the CP/M card were actually single board computers. The Geneve didn't even require a 99/4A console, just the PEB and an IBM PC or XT (not AT!) keyboard. The Geneve was 99.99% compatable with the 99/4A with the exception of programs requiring a rarely used and undocumented (or little documented) 9918A video mode. The Geneve sported higher resolution graphics with more colors and true bitmap modes, unlike the TI's "bitmap" mode that actually adresses the screen in 8x1 pixel, 2 color "characters".

The maker of the 80 column and CP/M cards suffered an editorial induced fate similar to Osborne. They allowed a computer magazine to test the cards with unfinished beta versions of the software. Orders dropped drastically after the review was printed. Shortly after releasing the cards and finished software to market, they went out of business due to lack of funds, and a lack of being able to make potential customers understand that the magazine had reviewed a pre-production system and that all the problems were fixed. Heh, today, if the computer media doesn't get to see your earliest versions and it's not full of bugs, people assume you don't even have a product, but they'll buy it anyway.

But the absolute weirdest, most expensive and most "Why?" peripheral was a box that allowed the 99/4A to be "PC Compatable". What it actually was, was a box that plugged into the side expansion connector and enabled the TI to play keyboard for an otherwise fully functional IBM PC clone, including a seperate monitor. It was essentially a very expensive TI-PC keyboard switch that just happened to come with a whole PC attached.

In a weird twist, years after TI discontinued the 99/4A, some company made an interface board and cover plate to replace the TI keyboard and provide a socket to plug in an IBM PC/XT (not AT!) keyboard.

Markian Zadony specifies:
The product Gregg Eshelman refers to that turned the TI into a PC-compatible was the "Triton Turbo XT", which came out in '87.  I remember drooling over this.  (The ad & product info are available at ).

Ricardo Fabián Portilla from Argentina, remembers:
In the middle of 1982 the TI99/4A black and silver model was imported from USA to Argentina. In 1983 started the local production of the TI99/4A beige model, made by SDT S.A. (an Argentinean computer company) between 1983-1986. The TI99/4A beige model was used in Argentina mainly for educational purposes (generally for teaching BASIC and programming concepts).

When used for teaching, the TI99/4A was used together with TI Extended BASIC (or the TI Logo) cartridge and the Expansion Memory Unit. A large quantity of software was available for this computer (TI Extended BASIC, a variety of games in cassette tapes, diskettes and cartridges (Parsec and Microsurgeon was my favorite games), TI Calc, TI Pascal, TI Logo (wide used for teaching), Home Financial Decision, Assembler Editor, and so on. Most of this software ran from cartridges, called Command Modules.

The Texas Instruments TI-99/4A was a little computer that was never really given a chance. It came out in Argentina around the same time as the Commodore 64 and the Sinclair ZX Spectrum, which eclipsed the TI99/4A. It was the first small personal computer to have a 16-bit address bus processor. It also had a Speech Synth module that sounded remarkably good.

Unfortunately, the TI-99/4A had several strikes against it: 
• Used a normal cassette player for storage. This requires fiddling with cables and volume levels. Commodore's dedicated Datassette player was much easier to use, and more reliable at writing and reading information.
• Required a large expansion box (known as Expansion Memory Unit in Argentina) in order to add memory. Even with expansion, BASIC programs only had 12K for code.
• Was rumored to be very slow (and it was very slow in BASIC due to its BASIC being doubly interpreted, but it was much faster at the machine language level).

The Expansion Memory Unit contained memory expansion cards, a disk drive, RS232 card and various other peripherals. However, many of the peripherials could be purchased separately and plugged directly into the console. Although the TI99/4A could be connected to any TV set, the Texas Instruments color monitor provided a much better quality picture.

This computer had very good features to make up to 32 moving sprites on the screen (using TI Extended BASIC), but does not had graphic commands to draw simple shapes (lines, circles, boxes, etc.)
For file managing on diskette, the TI99/4A must be used together with the Expansion Memory Unit and the Disk Manager cartridge. It allows to format, rename, copy and delete files on 5,25" diskettes.

One of the most negative points of the TI99/4A's keyboard was the location of the "FCTN" (function) and the "=" keys, because pressing both "FCTN" and "=" keys resets the computer (with no confirmation message). I remember, too often, instead of pressing "SHIFT" + "=" to write the + character on the screen, I pressed "FCTN" + "=" and it causes the computer to reset, many times with a large BASIC program on memory (of course) not saved on tape or disk yet!

When the TI99/4A reached the end of its life (around 1985-1986), it was replaced in Argentina by the MSX computers (which had the same video processor). From that years, MSX computers begun to be used for teaching MSX BASIC and MSX Logo. More than 20 years after having being created, the TI99/4A continues (and it will continue) being in the heart of whom we learned with it our first steps in the computers world.

Andy Frueh reports:
Many beige consoles WERE able to use third-party, unlicensed cartridges.
The earlier beige models used the same ROMs as the original black and silver model.
Later, in 1983, they produce the "v2.2" console. If the computer title screen displays that version number and a 1983 (rather than 1981) copyright notice, it has the third-party lockout (which some companies, such as Funware, were able to overcome anyway).

Click here to go to the top of the page   
Contact us | members | about | donate old-systems | FAQ
OLD-COMPUTERS.COM is hosted by - NYI (New York Internet) -