Thanks to the help of several fellow 99/4A enthusiasts (Rasmus and Tursi), I’m happy to announce an in-system software update for the F18A firmware. Currently the update program only runs on a 99/4A system and requires a bulk-storage device large enough to contain the update program, bit stream, and data file on the same “disk” […]
Anyone interested in using the F18A in their own computer or microcontroller system, please start with the TMS9918A datasheet since the electrical interface, host CPU interface, and timing specifications of the F18A are the same as the TMS9918A. I’m only going to outline the F18A differences here.
Since the F18A runs at a higher internal […]
0.0 F18A Register Use Spreadsheet
The register use spreadsheet is essential to programming the F18A and shows how all the extra VDP registers are used and what features they provide.
Download the F18A_Register_Use Spreadsheet
Programming the F18A is very similar to the original 9918A VDP. Because the F18A is a pin-compatible replacement for […]