Leaderboard

In the MPS2 it's IC5 and 10, it definitely needs IC10 because as you said it controls the reel comms. Now I have found that IC5 isn't always needed and it depends on the game (some will run and some won't) so it could be the same in MPS1 (IC6)?

1. There are 2 TMS9902, can the printer port one (IC6) be taken out and used for the reel comms (IC4) or will the MPS system error due to the missing chip. 2. This chip is used in several other computing systems, I can imagine a replacement would become popular. 3. The MPS uses it for reel comms, simple serial communications BUT it does multiplex TX/RX onto a single track. I wonder if a relatively simple hack can be made to just keep this comms running. I see TX/RX are combined after the TMS9902 and split with an inverter for the TMS7041 reel CPU. MAX232 to the rescue ???

Hi there! Thanks for your reply. The picture of the board was taken before cleaning. It has been in my ultrasonic cleaner. Tracks repaired. Replaced some parts. Gone to bed yesterday evening and woke up with a fresh head.. grabbed my multimeter and found out one logic had bad ground connection...DOH!! fixed that and plugged it in...yay!! Kicked the old and heavy CRT out and installed a fresh TFT screen It is fully working again and will soon belong to Geronimo