76 in 1 multicart - different revisions

[krzysiobal]

One of few n-in-1 multicarts, where there are really nn unique games. Runs as mapper 226.



A) 2xDIP32 1MB ROMs, vertically arranged


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B) 1x blob 2MB ROM


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C) 1x DIP42 2MB ROM


Different menu copyright text:
https://obrazki.elektroda.pl/1681249500_1598311250.png

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D) 1x blob+DIP42 2MB ROM


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E) 2xDIP32 1MB ROMs, horizontally arranged


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F) 4xDIP32 512kB ROMs


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G) 2xDIP32 1MB ROMs, horizontally arranged
Same as E but another revision of this PCB. 1 ROM chip is missing, no idea if menu is different or just half of games does not work.

[Killbox91]

I found a faulty cartridge like this.

ROM2 chip is empty/or faulty.

Menu appears but if I start anything again the menu disappears.

[krzysiobal]

I found a faulty cartridge like this.

ROM2 chip is empty/or faulty.

Menu appears but if I start anything again the menu disappears.

How the other side of PCB looks like?
Your description seems like the mapper cannot switch properly banks - either it is stuck in reset state or the writes to mapper register does not have any effects.

[Killbox91]

I found a faulty cartridge like this.

ROM2 chip is empty/or faulty.

Menu appears but if I start anything again the menu disappears.

How the other side of PCB looks like?
Your description seems like the mapper cannot switch properly banks - either it is stuck in reset state or the writes to mapper register does not have any effects.

Based on your request, I have attached both sides of the PCB.

If I write the bin files in the correct order into the 27c040 eprom, then 42 in 1 starts, but I can't even reset it to 76 in 1.

All games work regardless.

There is also an interesting video about it.(LINK)
https://www.youtube.com/watch?v=GLJ1AA_z3C0

[krzysiobal]

I found a faulty cartridge like this.

ROM2 chip is empty/or faulty.

Menu appears but if I start anything again the menu disappears.

HD-16 (ROM1) and HD-15 (ROM2) have the same signals wired as /CE and /OE so one of the ROMs need to have either positive +CE or positive +OE,
ROM2 (HD-15) has positive +CE (pin22). that's why you got FFs while trying to read is an ordinary 27040 eprom.
If you replaced it with ordinary eprom, you need to disconnect pin 22 of that eprom from the pin22 of solder pad and wire pin 22 of thats eprom to ROM4 (HD-68) pin 22

[Killbox91]

I found a faulty cartridge like this.

ROM2 chip is empty/or faulty.

Menu appears but if I start anything again the menu disappears.

HD-16 (ROM1) and HD-15 (ROM2) have the same signals wired as /CE and /OE so one of the ROMs need to have either positive +CE or positive +OE,
ROM2 (HD-15) has positive +CE (pin22). that's why you got FFs while trying to read is an ordinary 27040 eprom.
If you replaced it with ordinary eprom, you need to disconnect pin 22 of that eprom from the pin22 of solder pad and wire pin 22 of thats eprom to ROM4 (HD-68) pin 22

I tried what you wrote, but it didn't work.