Yes, that's right. At least for me the 32Mb SIMMs I have, they come with reversed.Actually, the 32Mb SIMMs have 2 x MBM29F016-90PFTR (Fujitsu 16Mb 90ns Reverse pinout) chips.
So, It is possible to convert an 32Mb SIMM into a 128Mb chip if you have 2 more MBM29F016-90PFTR AND 4 x MBM29F016-90PFTN (Fujitsu 16Mb 90ns Normal pinout) chips and optionally 6 x 100nF smt capacitors.
I've tried putting additional flash chips on a 32Mb SIMM without success because I was mix matching different vendor chips (Fujitsu, ST and AMD).
As Mitsurugi-w said, finding reverse pinout Fujitsu flash chips is almost impossible. BUT, if you have 2 x 32Mb SIMMs and 1 x 64Mb SIMM, you can use the PCB of one of the 32Mb SIMMs as a base and salvage the 2 reverse pinout flash ICs from the other 32Mb SIMM and 4 normal pinout ICs from the 64Mb SIMM.
You have to be skilled in surface mount desoldering and soldering though...
I'm sure Mitsurugi can help you on that.What about the possibility of fixing faulty simms?
I've got a 128M which won't flash, I suspect one of the chips has failed, I also have a 32M & 64M simm spare - could one working 128M be made out of that combination?
Would it be feasible to offer a simm rebuild service?
Would still need two chips.I also have a 32M & 64M simm spare - could one working 128M be made out of that combination?
If only one or two chips are dead on the 128M - surely there'd be enough on the other two to rebuild it or would I need 2 * 32M and 1 * 64M to guarantee a fix?Would still need two chips.I also have a 32M & 64M simm spare - could one working 128M be made out of that combination?
Well....honestly don't know if that was a good price.
Maybe it's time for CPS3 SuperBIOS v2...Well all you would need to do is write any simm with a single file using the SuperBIOS and then desolder the chip and read it in your programmer and then compare the data with the full file. Then note the offsets of each chip. If you write the simm using the SuperBIOS in the files menu and there is a bad chip it freezes and tells you the offset it froze at. So if you know what chip is responisble for each offset you can determine the bad chip.
Problem is my $700 Topmax 2 programmer does not support either of the chips on the SIMMs. The earlier revision of the Topmax did though. I might buy a cheaper programmer just to do this but I'd rather not have to. If someone else wants do this part for the community it would be awesome. Otherwise, I can around to it eventually.
And you might also would like to consider to modify the device ID checks to support more "up to date" flash IC brands.Maybe it's time for CPS3 SuperBIOS v2...Well all you would need to do is write any simm with a single file using the SuperBIOS and then desolder the chip and read it in your programmer and then compare the data with the full file. Then note the offsets of each chip. If you write the simm using the SuperBIOS in the files menu and there is a bad chip it freezes and tells you the offset it froze at. So if you know what chip is responisble for each offset you can determine the bad chip.
Problem is my $700 Topmax 2 programmer does not support either of the chips on the SIMMs. The earlier revision of the Topmax did though. I might buy a cheaper programmer just to do this but I'd rather not have to. If someone else wants do this part for the community it would be awesome. Otherwise, I can around to it eventually.
I'd like to add auto update of the code and speed up that damn long flashing process.....