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yann64andClaude Opus 5.5 b274874139 All machines linked to their forum thread (full comment import) 
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title, categories, types, origins, years, cpus, params
title categories types origins years cpus params
Texas Instruments TI 99 / 4A
Computers
Home Computer
U.S.A.
1981
TI TMS 9900
name image company company_name specs tabs forum_thread photos adverts hardware emulators links docs videos related oc_id source
TI 99 / 4A /media/museum/photos/texas-instrument_ti994a_1.jpg /companies/texas-instruments Texas Instruments
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NAME TI 99 / 4A
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MANUFACTURER Texas Instruments
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TYPE Home Computer
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ORIGIN U.S.A.
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YEAR 1981
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END OF PRODUCTION 1984
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BUILT IN LANGUAGE TI Basic
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KEYBOARD QWERTY full-stroke keyboard, 48 keys\ 2 x SHIFT, CTRL, ALPHA LOCK, FCTN
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CPU TI TMS 9900 (with 256 bytes 'cache', actually it accesses to 256 bytes of RAM)
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SPEED 3,3 MHz
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CO-PROCESSOR TMS 9918 (TMS 9929 in Europe) - Video / Sprite
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RAM 16 KB - Memory expansion card can be added : 4 KB or 32 KB (up to 52 KB)
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VRAM 16 KB
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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)
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TEXT MODES 32 x 24 (16 colors), 40 x 24 (2 colors)
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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)
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COLORS 16
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SOUND 3 channels, 5 octaves (110hz to 55khz) and 1 noise channel (periodic and white)
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SIZE / WEIGHT 38 x 25,5 x 6 cm / 2,15 kg
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I/O PORTS Tape interface, RGB video, Joystick (2), cartridge slot (Solid State Cartridge)
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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.
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POWER SUPPLY Special TI external PSU\ (pins 1,2 : 16v / 1,6A -- pins 2,4 : 8v / 0,15A)
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PRICE £99 (UK, 1983)
photos
adverts
hardware
emulators
links
docs
videos
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SIDE VIEW Notice the expansion port on the right side. /media/museum/photos/texas-instrument_ti994a_side-r_1.jpg
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VIEW FROM ABOVE The whole right part is the cartridge slot (Solid State Sotfware slot). /media/museum/photos/texas-instrument_ti994a_above_1.jpg
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VIEW FROM UNDER Ok,it's not that interesting, but hey, who knows ? Maybe someone's interested out there... /media/museum/photos/texas-instrument_ti994a_under_1.jpg
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FRONT VIEW /media/museum/photos/texas-instrument_ti994a_front_1.jpg
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PROFILE There is the joystick plug, so alone... /media/museum/photos/texas-instrument_ti994a_profile_1.jpg
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LEFT SIDE I guess you can spot the joystick plug ?! /media/museum/photos/texas-instrument_ti994a_side-l_1.jpg
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RIGHT SIDE You can easily spot the expansion port. /media/museum/photos/texas-instrument_ti994a_side-r_2.jpg
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REAR From left to right we have : - Cassette interface (DB9 !)\ - Power IN\ - RGB video out (DIN6) /media/museum/photos/texas-instrument_ti994a_rear_1.jpg
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COMPLETE SYSTEM Complete system with expansion box and vocal syntesizer module Thanks to **Blake Patterson** /media/museum/photos/ti_ti994a_completesystem_1.jpg
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U.S. ADVERT (1982) Advert said: Our Peripheral Expansion System gives you plug-in cards for memory expansion, P-Code capabilities, a disk drive controler and the RS-232 interface. You can also add a modem, speech synthetiser, disk drive and matrix printer... ... TI BASIC is built into the computer, but it can also handle TI Extended BASIC, UCSD Pascal, TI LOGO, TMS-9900 Assembly language and TI PILOT ... /media/museum/pubs/ti_ti994a_pub_1.jpg
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UK ADVERT (STUPID !) Dated august 1982 Thanks to [Howard Jones](http://wotsit.thingy.com/haj/) for this picture. /media/museum/pubs/texas-instrument_ti994a_pub_1.jpg
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FRENCH AD (JAN. 1983) "TI 88/4A. The family computer.\ It's easy. Connect it, connect yourself." /media/museum/pubs/ti_ti994a_pub_jogger.jpg
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FRENCH AD (SEPT. 1983) "The amazing TI-99/4A.\ A computer for 1800fr" /media/museum/pubs/ti_ti994a_pub_incroyable-1800fr.jpg
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FRENCH ADVERT *Texas Instruments home computer, simply unbeatable* Notice that the man seems not to feel at ease with a computer keyboard and still doesn't use the right finger... Thanks to **Charles da Silva** /media/museum/pubs/ti_ti994a_pub_imbattable.jpg
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UK ADVERT, OCT 1983 Probably the last advert made by T.I. in the UK /media/museum/pubs/ti_ti994a_pub_s2.jpg
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UK ADVERT, OCT 1983 Last sales in the UK. At the same time, a Commodore VIC-20 cost £139 and a Commodore 64 cost $229 /media/museum/pubs/ti_ti994a_pub_s1.jpg
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COMPLETE SYSTEM... TI-994A with expansion box, vocal synthesizer and acoustic coupler. /media/museum/hardware/texas-instrument_ti994a_complete.jpg
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5''1/4 DISK-DRIVES On this picture, there is two 5''1/4 disk-drives (or maybe just 1 with its controller). This particular setup is quite rare since different drives were produced to be included into the popular expansion box. /media/museum/hardware/texas-instrument_ti994a_diskdrives_1.jpg
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TI-99/4 COLOR MONITOR /media/museum/hardware/texas-instrument_ti994_color-monitor.jpg
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TI-99/4 PRINTER This Dot matrix printer was a rebadged version of the Epson FX-80 /media/museum/hardware/ti_ti994a_printer_1.jpg
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Mess emulator http://www.mess.org MS DOS Emulates all of the TI-99 versions, including the Geneve card
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PC99 http://pw2.netcom.com/~mjmw/index.html MS DOS Quality emulator for the TI 99/4A
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Classic99 http://www.harmlesslion.com/software/Classic99 Windows Open Source & freeware TI-99/4A emulator for Windows 9x
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Win994a http://www.99er.net/win994a.shtml Windows Win994a is a TI-99/4A simulator written by Cory Burr that installs and runs in Windows
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MacV9T9 official homepage http://perso.club-internet.fr/pytheas/english/MacV9T9.html Apple MacV9T9 is a TI99 emulator for the Macintosh
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planet-99.net http://www.planet-99.net/ Lots and Lots of 4A software on this site. Disks, Cartridges, Articles - the lot!
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Somtimes http://sometimes.99er.net/ Demo cartridges
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TI-99 4/A Webring http://e.webring.com/hub?ring=ti994a You know what it is ;-)
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TI-99 Forever ! http://www.ti99.com Excellent site by Fabrice Montupet
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TI-99/4 Home Page at 99er.Net http://www.99er.net/ THE us site to visit !
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Web Wiz CAPTCHA http://www.webwizcaptcha.com Tons of things here !
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USER'S REFERENCE GUIDE http://www.classiccmp.org/dunfield/ti/index.htm /media/museum/docs/couvs/texas-instruments_ti99-4a_user-reference-guide.jpg [**USER'S REFERENCE GUIDE**](http://www.classiccmp.org/dunfield/ti/index.htm)written by Texas Instruments  compiled/archived by Dave Dunfield\  type of document : PDF\  source : [Daves Old Computers](http://www.classiccmp.org/dunfield/)
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BEGINNER'S BASIC http://www.classiccmp.org/dunfield/ti/index.htm /media/museum/docs/couvs/texas-instruments_ti99-4a_beginners-basic.jpg [**BEGINNER'S BASIC**](http://www.classiccmp.org/dunfield/ti/index.htm)written by Texas Instruments  compiled/archived by Dave Dunfield\  type of document : PDF\  source : [Daves Old Computers](http://www.classiccmp.org/dunfield/)
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BASIC REFERENCE CARD http://www.classiccmp.org/dunfield/ti/index.htm /media/museum/docs/couvs/texas-instruments_ti99-4a_basic-reference-card.jpg [**BASIC REFERENCE CARD**](http://www.classiccmp.org/dunfield/ti/index.htm)written by Texas Instruments  compiled/archived by Dave Dunfield\  type of document : PDF\  source : [Daves Old Computers](http://www.classiccmp.org/dunfield/)
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GETTING STARTED WITH THE TEXAS INSTRUMENTS TI99/4A http://shawweb.myzen.co.uk/stephen/book.htm /media/museum/docs/couvs/vide.gif [**GETTING STARTED WITH THE TEXAS INSTRUMENTS TI99/4A**](http://shawweb.myzen.co.uk/stephen/book.htm)written by Stephen Shaw  compiled/archived by Stephen Shaw\  type of document : HTML\  source : [Stephen's Main Web Page](http://shawweb.myzen.co.uk/stephen)
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PROGRAMMING DISCOVERY IN TI BASIC STUDENT GUIDE http://www.99er.net/docs.html /media/museum/docs/couvs/texas-instruments_ti99-4a_programming_discovery.jpg [**PROGRAMMING DISCOVERY IN TI BASIC STUDENT GUIDE**](http://www.99er.net/docs.html)written by Texas Instruments Computer Advantage Club  compiled/archived by Rich at www.99er.net\  type of document : Unknown\  source : [TI-99/4A Home Computer Page](http://www.99er.net/)
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TI-99/4 CONSOLE SCHEMATICS http://www.99er.net/docs.html /media/museum/docs/couvs/texas-instruments_ti99-4_console-schematics.jpg [**TI-99/4 CONSOLE SCHEMATICS**](http://www.99er.net/docs.html)written by Texas Instruments  type of document : PDF\  source : [TI-99/4A Home Computer Page](http://www.99er.net/)
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TI-99/4A CONSOLE & PERIPHERAL EXPANSION SYSTEM TECHNICAL DATA http://www.99er.net/docs.html /media/museum/docs/couvs/texas-instruments_ti99-4a_technical_data.jpg [**TI-99/4A CONSOLE & PERIPHERAL EXPANSION SYSTEM TECHNICAL DATA**](http://www.99er.net/docs.html)written by Texas Instruments  type of document : PDF\  source : [TI-99/4A Home Computer Page](http://www.99er.net/)
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SPEECH SYNTHESIZER MANUAL http://www.99er.net/docs.html /media/museum/docs/couvs/texas-instruments_ti99-4a_speech-module-manual.jpg [**SPEECH SYNTHESIZER MANUAL**](http://www.99er.net/docs.html)written by Texas Instruments  type of document : PDF\  source : [TI-99/4A Home Computer Page](http://www.99er.net/)
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DISK MEMORY SYSTEM MANUAL http://www.99er.net/docs.html /media/museum/docs/couvs/texas-instruments_ti99-4a_disk-memory-system.jpg [**DISK MEMORY SYSTEM MANUAL**](http://www.99er.net/docs.html)written by Texas Instruments  compiled/archived by Rich at www.99er.net\  type of document : Unknown\  source : [TI-99/4A Home Computer Page](http://www.99er.net/)
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RS232 INTERFACE CARD MANUAL http://www.99er.net/docs.html /media/museum/docs/couvs/texas-instruments_ti99-4a_rs232.jpg [**RS232 INTERFACE CARD MANUAL**](http://www.99er.net/docs.html)written by Texas Instruments  compiled/archived by Rich at www.99er.net\  type of document : Unknown\  source : [TI-99/4A Home Computer Page](http://www.99er.net/)
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DATA RECORDER MANUAL http://www.99er.net/docs.html /media/museum/docs/couvs/texas-instruments_ti99-4a_data-recorder.jpg [**DATA RECORDER MANUAL**](http://www.99er.net/docs.html)written by Texas Instruments  compiled/archived by Rich at www.99er.net\  type of document : PDF\  source : [TI-99/4A Home Computer Page](http://www.99er.net/)
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TV commercial featuring Bill Cosby https://www.youtube.com/watch?v=OhsgvW9P7tI Length: 30 s
/museum/texas-instruments-computer-99-8
/museum/texas-instruments-ti-99-2
/museum/texas-instruments-ti-99-4a-beige
236
url date
https://web.archive.org/web/20230610144042/http://www.old-computers.com/museum/computer.asp?c=236 2023-06-10

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.

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