TMS9918A Video Upgrade: Part 1

The TMS9918A video project consists of two PC boards, a small modification/addition to the main computer board, and a +5, +12, -5 VDC power supply (an expansion board of some type is necessary). Video board “A” contains the TMS9918 VDP chip, 16K video ram and one support chip for I/O interfacing. Board “B” contains the TMS9918A enhanced BASIC 2764 EPROM, a switchable 2764 EPROM (8-16K) socket and the logic necessary to decode the system and bank switch the character generator space (for initialization and printing to the 2040 printer).