Beggar Prince (first revision) hangs after SFT screen

[Former user]

Original issue 326 created by 0vetal0 on 2013-02-26T14:36:31.000Z:

What steps will reproduce the problem?
1. run the game)

What is the expected output? What do you see instead?
after SFT-logo screen fades and game hangs

What version of the emulator are you using (official, SVN revision,...)?
RetroArch win32 x86 + selfcompiled from current git libretro GenPlusGX port
the same issue with last "official" libretro-git-genplus-x86.dll (from 17.02.2013)

[Former user]

Comment # 1 originally posted by 0vetal0 on 2013-02-26T14:39:09.000Z:

rom used - size="4194304" crc="f3af46cd" sha1="f481b970756c482d8f408c4bab8902172837e7d8"

[Former user]

Comment # 2 originally posted by ekeeke31 on 2013-02-26T15:05:40.000Z:

The emulator actually only supports the last revision of this game, which as far as i know, is not publically available.
The dump you are using, which was only dumped recently, is from the first revision and has a few hardware differences.
Since the internal name is the same, the emulator misdetects your rom as the later revision and try to emulate inappropriate cartridge hardware, which makes it crash.

Until this old revision hardware is emulated, you can make it somehow works like in other emus by hexediting your rom and replacing the first occurence of "SF-001" by something else. Note that since the hardware in the cartridge is not emulated for this one, it will still randomly crash later in the game and internal saves are not going to work (same would happen with any emulator not emulating the protection).

[Former user]

Comment # 3 originally posted by 0vetal0 on 2013-02-26T15:37:13.000Z:

thanks for explanation, as quick fix I've made
/* 32K static RAM mirrored into $3C0000-$3FFFFF (odd bytes only) */
for (i=0x3c; i<0x40; i++) <= i<0x3f
and game works without reboot (at magican house), but indeed saves not working, moreover I dont see any SRAM access attempts...

[Former user]

Comment # 4 originally posted by ekeeke31 on 2013-02-26T16:22:58.000Z:

I know SRAM is mapped above ROM area in this first board revision (same as original chinese cartridge), at $400000-$4xxxxxx

[Former user]

Comment # 5 originally posted by 0vetal0 on 2013-02-26T18:26:57.000Z:

thanks for info, this was weird decision to use 4xxxxx area and probaly couse problems with SegaCD

[Former user]

Comment # 6 originally posted by ekeeke31 on 2013-02-26T19:31:03.000Z:

Indeed, that was the point of the later revisions.

Anyway, support for the early board revision has been added in r764