Home Computer TI-99/4A
Halleluya
Released:June 1981
Price: US$525 (without monitor)
How many:2.8 Million
CPU:TI TMS9900, 3MHz
Memory:16K RAM, 26K ROM
Sound: 3: channels + effect
Joystick: 2
Display:Video via an RF modulator 32 characters by 24 lines text 192 X 256, 16 color graphics
Ports:ROM cartridge (on front) Data storage cassette Audio/Video output Joystick input CPU bus expansion
Peripherals:Speech Synthesizer Peripheral Expansion Box Data storage cassette 300 baud modem
OS:ROM BASIC
TI99-4A Main BOARD
| 1 | TMS9900 CPU central process unit |
| 2 | TMS9918A VDP video display processor |
| 3 | TMS9901 HW Interface |
| 4 | Grom Chips CD2155/CD2156/CD2157 |
| 5 | TMS9919/SN94624 Sound Chips |
| 6 | 8 x TMS4116 RAM Chips |
| 7 | TMS9904 Clock Generator |
| 8 | 2 x 4k ROM chips (1501392-26) |
| 9 | 2 x 128 byte MCM6810P Scratch-pad RAM |
| 10 | Command Module Connector ( cartridges ) |
| 11 | Cassette Port |
| 12 | Video Port |
| 13 | Joystick Port |
| 14 | Keyboard Connector |
| 15 | Expansion Port |
TROUBLESHOOTING
https://www.ninerpedia.org/wiki/Troubleshooting
