SRAM Shenanigans (Bugzilla #41)

[GerbilSoft]

status IN_PROGRESS severity enhancement in component gens for II 1.0_beta1
Reported in version unspecified on platform All
Assigned to: David Korth

Original attachment names and IDs:

• psyofail_saving.png (ID 14)

On 2011-02-28 18:38:04 -0500, Pietro Gagliardi (andlabs) wrote:

Some SRAM things to fix

On 2011-02-28 18:47:25 -0500, Pietro Gagliardi (andlabs) wrote:

ok how did that happen o_O

When disassembling Psy-O-Blade, I noticed its SRAM header area was bad:
0001B0:5241F820 20000020 00010020 3FFF2020
I'm not exactly sure what the consequence of this is, but the header is still bad =P

Puggsy detects SRAM and aborts (anti-piracy measure); the option is nice but turning it off automatically would be optimal.

Xin Qigai Wangzi (the original Chinese game Super Fighter Team translated as Beggar Prince) was written without knowledge of the Sega CD/32X clobbering areas above the cart and stores SRAM at $400000; this will need to be fixed. (Some, if not all, versions of Beggar Prince also has that bug; if those ever do get dumped, those will need to be added to the fix).

Genesis Plus/GX seems to have all this done already:
http://code.google.com/p/genplus-gx/source/browse/trunk/source/cart_hw/sram.c?r=455

On 2011-03-03 14:39:21 -0500, David Korth wrote:

commit SHA: b25dac9
Author: David Korth [email protected]
Date: Thu Mar 3 14:23:27 2011 -0500

[libgens] Rom::initSRam(): Disable SRAM for Puggsy.

Puggsy will show an anti-piracy message after the third level
if SRAM is detected.

I also added some code for two more hacks I'm going to test later.
They're currently disabled via #if 0 / #endif.

Hacks:
- Psy-O-Blade: Incorrect SRAM header.
- Xin Qi Gai Wangzi (Beggar Prince): No header; non-standard location.

On 2011-03-03 14:40:05 -0500, David Korth wrote:

commit SHA: 9329600
Author: David Korth [email protected]
Date: Thu Mar 3 14:31:37 2011 -0500

[libgens] Rom::initSRam(): Added a hack for Psy-O-Blade.

Psy-O-Blade has an incorrect SRAM header that causes Gens/GS II to think
SRAM starts at $000000 and ends at $00FFFF. (It seems like they left out
a few bytes in the addresses.)

This hack fixes the SRAM addresses for Psy-O-Blade by adjusting them to
$200000 and $203FFF.

This bug was reported by andlabs on the Gens/GS Bugzilla:
http://gs_server.gerbilsoft.ddns.info/bugs/show_bug.cgi?id=41

On 2011-03-03 22:32:03 -0500, Pietro Gagliardi (andlabs) wrote:

Created attachment 14
Psy-O-Blade "saving...finished

On 2011-03-03 22:38:17 -0500, Pietro Gagliardi (andlabs) wrote:

Just tested that... Psy-O-Blade isn't saving. The OSD save message doesn't come up, the game says "saving...finished" (see attached), and continuing from the title screen takes me back to the intro cutscene. For good measure, I tried Kega Fusion 3.63i — it behaves properly there.

[GerbilSoft]