What is Ti-99/4a?
1.
An early home computer (which pre-dates the term "PC") release by Texas Instruments in June of 1981. The TI99/4A computer sold for $525, without a monitor. Specs included:
RAM: 256 bytes - Memory expansion card can be added : 4 KB or 32 KB (up to 52 KB)
ROM: 26 K
VRAM: 16K
Built in software: TI Basic
Processor: TMS9900
Clock: 3.3 MHz
Video:
NTSC: TMS9918A/TMS9928A, PAL/SECAM: TMS9929A, 256 x 192, 64 x 48, 32 x 24. 16 Colors available. Standard mode: 24 lines and 32 columns of 8x8 pixel characters, with 2 colors (foreground and backgroud) per group of 8 characters. Text mode: 24 lines and 40 columns of 8x6 pixel characters. Monochrome display: 2 colors (foreground, background) for all characters. No sprites. Multicolor mode: 48 lines and 64 coloumns of 4x4 boxes. Each box can have its own color. Graphic mode: 192 lines and 32 columns of 1x8 pixels "characters". Each character can have its own set of two colors. In addition, the VDP can handle up to 32 sprites. Each can have a color of its own (background is always transparent).
Color Palette: 16
Sound:
TMS 9919 Complex Sound Generator. The sound chip can emit simultaneously up to 3 tones and 1 noise (which can be a periodic or a white noise). The theoretical frequency range is from 28 Hz to 111 kHz and the volume can be adjusted on a scale of 0 to 15.
Interfaces:
1 x Cartridge, 1 x Expansion Port, 1 x Composite Monitor Out, 1 x Cassette Interface, 1 x Joystick (non Atari compatible)
Disk drive:
No built-in drive.
Power supply:
External
Many a programmer learned to write code on a TI-9/4a.
