Click Here to visit our Sponsor
The Latest News ! The History of Computing The Magazine Have Fun there ! Buy books and goodies
  Click here to loginLogin Click here to print the pagePrinter ViewClick here to send a link to this page to a friendTell a FriendTell us what you think about this pageRate this PageMistake ? 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
C64 maze generator T-shirts!

see details
Spiral program T-shirts!

see details
BASIC code T-shirts!

see details
Pixel Deer T-shirts!

see details
Pak Pak Monster T-shirts!

see details
Pixel adventure T-shirts!

see details
Vector ship T-shirts!

see details
Breakout T-shirts!

see details
Shooting gallery T-shirts!

see details





T > TEXAS INSTRUMENTS  > TI 99 / 4A   


Texas Instruments
TI 99 / 4A

The Texas Instrument TI 99/4A was a very succesful computer. A large number ROM cartridges (36 KB each) were developped for this computer, as the popular Extended Basic.

Up to seven peripherals could be connected : 32 KB RAM extension, RS232c, Disk controler (90 KB per disk, up to 3 disk-drives), speech synthetiser, Peripheral Expansion box, and so on... One item of note is that the bus architecture for the Peripheral Expansion box (PE) was the basis for the NuBus used in the later Macintosh computers.

_________

Contributors : Stephen Boutillette

Ben Yates says :
The TI VDP had 16K of dedicated VRAM, outside of the CPU RAM memory map.
The 99/4A has 4 VDP modes :
1. Graphic I (32x24, 255 redefineable characters, 16 colors, 1 background and 1 foreground color for each character set of 8 characters, 8x8 character matrix)
2. Text mode (40x24, foreground/background colors out of 16)
3. Multicolor (weird 48 x 64 mode, 4x4 unicolor character matrix)
4. Bitmap - same as 1, except 768 characters and each character can have a foreground and background color (of 16) for each pixel row of that character.


David Stites adds:
You list the TI 99/4a as being released in June 1979. At about that time I purchased a TI 99/4 for around $700. Besides the built-in BASIC and the firmware cartridges it had a third function called an Equation Calculator. I never used it and when the computer went insane they replaced it with the /4a for $50. The /4a didn't have the Equation Calculator.



ShareThis


 

In September, 1979, I went to work at Texas Instruments in Lubbock, Texas, where the TI-99/4 and 99/4A was mostly manufactured. I was an electronic technician and did soldering and wire-wrap on prototypes in development, mostly software cartridges and add-on devices, as well as worked in testing, repair, burn-in (each new system was left on for several days, I think it was, then re-tested). And I helped train people on the assembly line. I did the wire-wrap prototype version of the speech synthesizer module$ a female engineer designed it$her name escapes me at the moment. .That speech synthesizer was a big deal for its time. She and I were the only two women in that module (and most of the rest of TI) who weren''t assembly line workers

Even though I worked on those computers, I could not afford to buy one for myself! Lordy, they were about $1,700 with all the extras such as the cassette tape drive, if I remember correctly, a fortune back then. But I did have a system at work to use! Much different than programming in FORTRAN on a mainframe!

In those days, another "module" or modular building at TI actually repaired people''s broken calculators and mailed them back to the user. Imagine that.

TI had these automated mail robots that followed a special painted line on the floor, in and out of modules and up and down the big hallway. We used to put stuff in front of them to see what would stop them and what wouldn''t. For 1979, it all was very futuristic to me.

Later, I moved to the Front End module to make more money, where I ran a boron/phosphorus ion implant machine, one of the several hundred processes in creating semiconductor chips. The implant machines were these huge particle accelerators that were the crankiest machines I ever worked with. The chips have multiple layers, and these machines placed a positive or negative charge on the unmasked areas of a chip''s layer. We made the first 256k memory chips there! Then I went back to college after I made enough money, and left TI and Lubbock, which were both good to me.

          
Friday 18th August 2017
Loretta M. (California, USA)

Ahhh the old tank TI 99/4A. So well built and so underappreciated. It actually plays games well and many of its educational software like Plato and the GROM carts were quite good for their time. If it only weren''t for that infernal PEB. That monstrosity is just a lump on the desk. Shame Custodio Malilong doesn''t make the fabulous microPEB anymore. Such a great device and so small. But if anything, he deserves great recognition for his device and making the TI more useable.

          
Saturday 3rd September 2016
Deathstrike

The TI-99/4a was a follow up to the TI-99/4, which is missing from the museum. The machine was at its time the most powerful on the market, at 16-bits and screaming fast, but TI mandated that everything developed for it had to go through the GPL interpreter, which slowed program flow to start with. But the BASIC interpreter was written in GPL, so it was double interpreted, making it the slowest executing BASIC ever released. And TI sought to keep all software release in house, which proved to be a horrible business model, as has been seen more than once over the years.

          
Saturday 30th August 2014
jt august (missouri, usa)

 

NAME  TI 99 / 4A
MANUFACTURER  Texas Instruments
TYPE  Home Computer
ORIGIN  U.S.A.
YEAR  1981
END OF PRODUCTION  1984
BUILT IN LANGUAGE  TI Basic
KEYBOARD  QWERTY full-stroke keyboard, 48 keys
2 x SHIFT, CTRL, ALPHA LOCK, FCTN
CPU  TI TMS 9900 (with 256 bytes 'cache', actually it accesses to 256 bytes of RAM)
SPEED  3,3 MHz
CO-PROCESSOR  TMS 9918 (TMS 9929 in Europe) - Video / Sprite
RAM  16 KB - Memory expansion card can be added : 4 KB or 32 KB (up to 52 KB)
VRAM  16 KB
ROM  26 KB  : 8 KB ROM connected to the CPU + 18 KB ROM in byte-serial bit-mapped circuits (usually known as GROM, Graphic Only Memory)
TEXT MODES  32 x 24 (16 colors), 40 x 24 (2 colors)
GRAPHIC MODES  Multicolor mode : 48 x 64 with 16 colors
256 x 192 with 16 colors (only accesed via machine code)
Sprites (only with TI-Extended Basic)
COLORS  16
SOUND  3 channels, 5 octaves (110hz to 55khz) and 1 noise channel (periodic and white)
SIZE / WEIGHT  38 x 25,5 x 6 cm / 2,15 kg
I/O PORTS  Tape interface, RGB video, Joystick (2), cartridge slot (Solid State Cartridge)
OS  TI's own system, but a p-code card could be added, which gave access to the UCSD p-system and a Pascal compiler.
POWER SUPPLY  Special TI external PSU
(pins 1,2 : 16v / 1,6A -- pins 2,4 : 8v / 0,15A)
PRICE  £99 (UK, 1983)


retro computing t-shirts and goodies
3D Cubes
BASIC code
Breakout
C64 maze generator
Pak Pak Monster
Pixel adventure
Pixel Deer
Ready prompt
Shooting gallery
Spiral program
Vector ship

Related Ebay auctions in real time - click to buy yours







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