Genesis reproduction problems.

A place that you can discuss reproduction of classic titles or "licensed-for-reproduction" homebrew for personal use.

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icemanxp300
Posts: 159
Joined: Thu May 14, 2015 6:17 pm

Re: Genesis reproduction problems.

Post by icemanxp300 » Thu Jul 21, 2016 9:31 pm

Ok so I put a Megaman Wily Wars on a board and it will not save. I'm not having a huge amount of luck getting proper data sheets for these chips. On the normal board that I generally use the game will save. The Microchip 337 1026B is on the pcb that normally saves.

The other pcb has this 6162 5950 and that will not save. Now both pcbs have a new battery installed and both output 3.3V. I should note the pcb that will not save is a dual rom donor and I am only using 1.

I know I should ditch the effort and use it on a non-save game but it's bugging me now and I need to figure out why it doesn't save. I'll post a few pics of the 2 different chips and of the pcb that does not save.

I should note I pin traced both chips and they go to the same locations on both pcb's.
sram chips.jpg
100_5160.JPG
100_5161.JPG
...
Last edited by icemanxp300 on Sat Jul 23, 2016 7:29 am, edited 1 time in total.

lidnariq
Posts: 8792
Joined: Sun Apr 13, 2008 11:12 am
Location: Seattle

Re: Genesis reproduction problems.

Post by lidnariq » Thu Jul 21, 2016 11:38 pm

Despite the logo, that is not Microchip. It's Mitsumi, and the part # is MM1026.

The other part is made by Rohm and its part number is BA6162.

icemanxp300
Posts: 159
Joined: Thu May 14, 2015 6:17 pm

Re: Genesis reproduction problems.

Post by icemanxp300 » Fri Jul 22, 2016 9:19 am

lidnariq wrote:Despite the logo, that is not Microchip. It's Mitsumi, and the part # is MM1026.

The other part is made by Rohm and its part number is BA6162.

I thought that logo was a little off but it was all I could come up with. Thanks for the info.

I don't think those reset chips have anything to do w/the problem.

found this info.

"Here is a list of games using "hidden" SRAM. By hidden, I mean that the location of SRAM overlaps the location of ROM. There is an internal logic based bank-switching method specific to the cartridge. Games having 3MBytes+ ROM and SRAM typically have these special carts."

For some reason even removing the 2 extra chips and rewiring the top right chip to mirror the other board still didn't work. I must have missed a trace or something? I even bridged the same legs as on the working board and it would not play the game. I will never use that board for a save game like this anyhow so I put it back together lol.

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