A short video showing how to fit a voltage regulator on the 161 in 1 multicart. It’s slightly different from the other carts in that it requires one of the diodes to be left in place in order to feed ~4.3v to one of the CPLDs. It looks to me like the Z80 related NVPROM chips are probably over voltaged due to the use a 5v type CPLD – I could be wrong but I suspect that’s why 4.3v has been used, as it won’t work at 3.3v and would be dangerous for the NVPROM at 5v. I suspect the logic levels to the M1 address lines won’t be 4.3v but will have dropped vs what they would be by feeding 5v into the CPLD.
The voltage regulator I fitted was AMS1117 3.3v 1A, not the larger LDO regulator shown at the start of the video.
138 in 1 and 120 in 1 pics:-
161 in 1 pics:-
Post time: Jun-28-2017