M5M51008BP-70LL SRAM CMOS memory workaround/alternatives

[FvM]

x51 processors have maximum 64k XRAM space. Larger memory can be accessed by bank select, you need to examine the circuit (particularly connection of RAM address lines) or the code to understand if multiple memory banks are used.

 

[hil987]

Interesting fact is that newer model of the same unit had twice as much SRAM memory and from what I know there is very little difference between two versions. New version had better firmware which allows transfer certain programs to the memory card where's the one we have only lets you transfer all or nothing.

Sadly the board of these machines users is so small it's almost impossible to get any valuable data..

I also though of raplcing 32 KB memory card's chip to twice the size, but we would need to sacrifice one of the cards for this idea. At the moment these cards sell for 100 euro each, so pricy game.

 

[FvM]

Sadly the board of these machines users is so small it's almost impossible to get any valuable data.

Small is relative. Post #20 photo looks overseeable. You can surely extract the netlist with a continuity tester.

 

[hil987]

Small is relative. Post #20 photo looks overseeable. You can surely extract the netlist with a continuity tester.

Sorry, I meatn there must be very few people who still using this type of unit!

 

[FvM]

Sorry, didn't read carefully.

There are apparently no users of this cable testers out there on Edaboard. Anyway, it should be possible to decode the memory configuration established in the board hardware.