Irem G-101 - NESdev BBS

Irem G-101
by naruko on 2013-10-02 (#118902)

メジャーリーグの例外的実装を調査しました。
http://w.livedoor.jp/famicomcartridge/d/Irem%20G-101

メジャーリーグでの要点は下記です。
- nametable mirroring は #1 固定の配線
- $9000 のレジスタはハード側で 0 に固定される

他に質問や間違いがあったらお知らせ下さい。

Re: Irem G-101
by etabeta on 2014-02-09 (#125276)

thanks a lot, naruko!
thanks to your notes, I have found out that I was not handling correctly the fixed PRG banks in MESS for this board: once I fixed those, Ai Sensei no Oshiete finally started to work!

I think I spot a mistake, though

Quote:

[program ROM #0 or #2 bank mode and mirroring register]
bit assignments
---------------
1 VRAM mirroring (0:V, 1:H)
0 select switchable bank (0:#0, 1:#2)

isn't this the opposite, i.e. bit 1 for selecting PRG bank to switch and bit 0 for mirroring?

Re: Irem G-101
by naruko on 2014-02-09 (#125285)

Hello,
This is my mistake. I'll fix my document. Thank you.