Coleco  Coleco Adam

The Coleco Adam computer

The Coleco Adam is an 8-bit home computer released by Coleco in 1983. It was developed as a successor of the ColecoVision console. When it was introduced at the Consumer Electronics Show in 1983 it was shown running a port of the ColecoVision game Donkey Kong. This caused some trouble as it was Atari which had the exclusive rights to the game for the home computer market, Coleco only had a license for game consoles. In the end Coleco had to sign an agreement to not sell the Adam version of the game.

A lot of software for the Adam was derived from the ColecoVision as a lot of the hardware is the same. In addition, the Adam can run CP/M and had dedicated support processors (3 Motorola 6801s @1MHz) to control Memory I/O, the keyboard, and the tape interface. There were 3 internal expansion slots, 1 external cartridge slot and a half-duplex serial bus called AdamNet that ran 62.5kBit per second.

Later Coleco produced a conversion kit, that would convert the ColecoVision to a full Adam computer

TMS9918 Series Video Display Processor (99n8, 99n9, 91n8, 91n9)

The TMS9918 is a series of video display controllers (VDC) manufactured in 1979 by Texas Instruments, also refered to as 'Video Display Processor' (VDP). The TMS9918 and its variants were used in the ColecoVision, CreatiVision, Memotech MTX, MSX, NABU Personal Computer, SG-1000/SC-3000, Spectravideo SV-318, Spectravideo SV-328, Sord M5, Tatung Einstein, Texas Instruments TI-99/4, Casio PV-2000, Coleco Adam, Hanimex Pencil II, and Tomy Tutor.

Key Features:

  • 256x192 pattern based color pixels per screen
  • 16 different colors
  • 8-bit memory mapped CPU interface
  • No need for DMA, CPU can access VRAM
  • 32 single color Sprites per screen (4 per scanline)


  • TMS9918A - 60Hz output, NTSC video
  • TMS9928A - 60Hz output, YPbPr video
  • TMS9929A - 50Hz output, YPbPr video
  • TMS9118 - Different RAM than TMS9918A, otherwise identical
  • TMS9128 - Different RAM than TMS9928A, otherwise identical
  • TMS9129 - Different RAM than TMS9929A, otherwise identical

Released 1983 Country Missing Information Brand Type COLECO Adam Name Coleco Adam CPU Class Z80 CPU Zilog Z80A @3.58MHz Memory 64kB RAM, 16kB VRAM, 32kB ROM Sound Chip Texas Instruments SN76489AN Sound 3 wave channels + white noise Display Chip Texas Instruments TMS992A VDP Display 40x24 text
32x24 16 color text, pattern based
256x192 16 color, 2 color per 8 pix.
Sprites 1 color, 16x16, 4/scanline, 32 total System OS Proprietary
Related Systems
Coleco Adam
Coleco  Adam (1983)
World Wide Web Links
WikiPedia: The TMS9918 Video Processor
Wikipedia page about the TMS9918 Video Display Controller (VDC) used in many computers such as MSX, ColecoVision, Nabu, Sord, TI-99 and more