Search found 4 matches

by Tauwasser
Mon Dec 17, 2018 5:17 pm
Forum: GBDev
Topic: GB & GBC Games Likely to Fail in your Emulator or Flash Cart
Replies: 27
Views: 25936

Re: GB & GBC Games Likely to Fail in your Emulator or Flash

rather an off-the-shelf counter 74HC161A used as a flip flop. Is this the same as Wisdom Tree's mapper? (GB.A14 = 161./LatchEnable ; GB./WR = 161.↑Clock) As far as I'm aware the Wisdom Tree games use SN74LS377N, which is an octal flip flop. However, the M161 games can disable the mapping by writing...
by Tauwasser
Mon Dec 17, 2018 12:55 pm
Forum: GBDev
Topic: GB & GBC Games Likely to Fail in your Emulator or Flash Cart
Replies: 27
Views: 25936

Re: GB & GBC Games Likely to Fail in your Emulator or Flash

I'm honestly unclear how exactly the mapper works to wall in a game to its own space within the ROM, but masking bits seems to have something to do with it. That MMM01 page is the only page with hard information about the chip, but while the information on that page seems technically more precise t...
by Tauwasser
Thu Aug 30, 2018 1:15 pm
Forum: GBDev
Topic: GB & GBC Games Likely to Fail in your Emulator or Flash Cart
Replies: 27
Views: 25936

Re: GB & GBC Games Likely to Fail in your Emulator or Flash

I believe one of the first things that all known MMM01 carts do when they are booted up is to write to the multiplexer bit in the Mode Register. This switches control from the first 32KB bank to the last 32KB bank by outputting ROM A19-20 to CPU A13-A14. I think this is why an emulator like bgb nee...
by Tauwasser
Thu Aug 30, 2018 11:14 am
Forum: GBDev
Topic: GB Bootleg 32-in-1 Cart
Replies: 5
Views: 6992

Re: GB Bootleg 32-in-1 Cart

Beware I made that schematic by eye! In hindsight, I should probably have written that the ROM is COB, and not in a package.