[BUG]: DJbox (Japan) - SCPS-15082 - 56275BE9

[spacemul]

Describe the Bug

Just black screen at start

Reproduction Steps

Just launch the game

Expected Behavior

No response

PCSX2 Revision

1.7.2120

Operating System

Windows 10 (64bit)

If Linux - Specify Distro

No response

CPU

Ryzen 5 3600

GPU

RTX 3070

GS Settings

No response

Emulation Settings

No response

GS Window Screenshots

No response

Logs & Dumps

No response

[ghost]

Same as the other thread, with a blockdump, we can see what is wrong with the game.

[spacemul]

DJbox (Japan) (2021-11-16 20-23-05).zip

[ghost]

Thanks, actually I run out of block if I enable the timing hack or the EE interpreter with the cache enabled, does those options work for you?

[spacemul]

I tried these 2 options but only black screen here on 1.7.2133

[Goatman13]

Game unpack/decrypt EE overlays with use of FPU. That result in corrupted mips code overlays on pcsx2. This has been tested on different emulator with softfloats available and function that generate inaccuracy is located at 0x128268. Since pcsx2 add/sub is accurate and function don't use div/sqrt/rsqrt, this is most likely mul inaccuracy. Game was additionally tested with old fpu mul mantisa hack, but it is not enough to fix it.

Just in case, it doesn't seems to be clamaping issue.

Reproduction Steps Launch game. Check unpacked code at 0x2821E0, 00282714, etc. This isn't only corruption that happen of course. To additionally confirm issue you can check the same code when game is launched with nearest rounding mode, code is completely broken then (initial jump at 0x100E24).

[refractionpcsx2]

Yeah I think kr_ps2 looked at this with me and said it did a while decryption routine but pcsx2 is just slightly out a bunch of times which ruins it