Page 1 of 1

シルヴァ・サーガ / Silva Saga PCB scan

Posted: Mon Feb 24, 2014 3:12 am
by naruko
PCB class: Nintendo HVC-TKROM-03
U1 PRG: KKS-SR-0 PRG, ROM 0x40000 byte, CRC32: 0xfe94066d
U2 CHR: KKS-SR-0 CHR, ROM 0x40000 byte, CRC32: 0x45c35b65

high resolution and other sides scan

Many emulators display illegal save datas at first time. This ROM images is marked as 'Baddump' in some databases. This is wrong. Many emulators don't emulate 'uninitialized' SRAM data.

- .sav file がない場合、エミュレータは $6000-$7fff を 0 で埋める。
- Silva Saga の Program は $6000-$7fff が 0 で埋まっていると「正常」なデータと認識するので、セーブデータの初期化をしない
- 「正常」と認識されたデータは実際には「不正」なのでゲームが進行しない

対策: non volatile data (SRAM) の初期値を 0 で埋めてはいけない

Re: シルヴァ・サーガ / Silva Saga PCB scan

Posted: Fri May 02, 2014 2:29 am
by etabeta
it took a lot of time, but I managed to implement per-game SRAM support when loading from software lists
this finally allows Silva saga to be playable in MESS (and I will soon use it for a couple of SNES games which need it as well)

thanks a lot for the info