Major Site Sections

Texas Instruments TI-99/4A (No "Solid State Software" Label)

	Company: Texas Instruments
	Model Number: PHCOO4A
	Manufacture Date/Year: 1981

	Camera Used: Nikon D5100
	Images Copyright: Click Here

Specifications

Core Unit:

Processor: 3 MHz TI TMS9900
Memory:
- 16K VDP RAM (Video Display Processor RAM)
- 256 bytes CPU fast "scratchpad RAM" intended for the processor to maintain register workspaces
- 26K ROM
Graphics:
- TI TMS9918A VDP
- 32 single-color sprites (8 x 8 pixels or 16 x 16 pixels)
- 16 fixed colors (15 visible, one color reserved for background color)
- Text Mode:
  - 40 × 24 characters (40 characters wide, up to 24 lines of text)
  - 256 6 × 8 user-definable characters, no sprites, foreground and background color only, not accessible in BASIC
- Graphics Mode:
  - 32 × 24 characters
  - 256 8 × 8 user-definable characters, full 15 color palette plus background (available in groups of 8 through the character table)
  - 32 sprites (only mode available in BASIC, Extended BASIC is required for sprites and can access only 28 sprites)
- Bitmap Mode:
  - 192 x 256 pixels
  - No more than 2 colors in an 8 pixel row, full 15 color palette plus background
  - All 32 sprites available but interrupt-based motion through the ROM routine is not due to the memory layout, not available to BASIC
- Multicolor Mode:
  - 64 × 48 pixels
  - Each pixel may be any color
  - All 32 sprites are available
Sound:
- TI TMS9918A VDP
- 3 voices, 1 noise (white or periodic)
- Voices generate square waves from 110 Hz to approximately 115 kHz
- Console ROM includes interrupt-driven music list playback
Ports and Expansion Slots:
- Controller
- Audio/video output
- Data storage cassette
- ROM cartridge slot
- CPU bus expansion