It was from a 6.60 fw was well. Although I am beginning to wonder if it is possible to drop a PS1 bios through the Vita if that bios maybe any more different, so many possibilities
Not sure what you mean @Clarkyk ?
I’ve been looking for references to this, as I can’t believe this more optimised BIOS has been hiding in plain sight for years.
Here’s the earliest one I’ve found, from 2007. It mentions that the bios has the CD player and memory card manager removed for a start.
https://www.ngemu.com/threads/bios-used-for-psx-emulation-on-psp.92778/
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Interesting
What’s the BIOS hash (MD5, or CRC) btw?
Did you test it with Mednafen PSX as well (he was using PCSX ReARMed btw)?
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Sorry if my comment through you off. I was wondering if a PS1 bios dumped though a Vita would be any different to the PSP extracted bios or not.
As for the information you dug up, seems interesting the MC manager and CD player are removed ( useless for most anyway) as I always thought some trace may have been left in case. I will have to try turning off the skip bios to see if the boot up screen loads
@sergio-br2 The BIOS from my PSP:
- CRC32: cc82b93b
- MD5: 32c04484c234fd09d79625e9fe2ec232
- SHA1: b8c96eefcaedd3f8ae2a58d71671364703caaa25
And another one around the web:
- CRC32: 5660f34f
- MD5: c53ca5908936d412331790f4426c6c33
- SHA1: 96880d1ca92a016ff054be5159bb06fe03cb4e14
I have tested it with the core, as a substitute for the eu bios, and my system it works. On my wife’s slower system (from 2007) it makes most of the games usable, but the music still stutter, but not as bad as without. Also the one I found doesn’t seem to contain a bios logo when used, you get the sound when the logo should play but no visuals
I think I found the same one, as the Bios boot screen went right into the PS black bg, skipping the white Sony diamond logo, ans that is a showstopper for me; I have weakness for displaying boot screens. Havent noticed a difference with the games I tested. If you know of one or two that is noticeable, share the names.
Wouldn’t it be possible for some kind of graphical blacklisting? for example, effect x doesn’t get rendered or shader y doesn’t get rendered…you know… I can’t say i saw any difference between bios’es, performance wise, maybe there’re graphical differences? I should test some games. Which games did you guys saw better performance?
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CRC32: 5660F34F
XXH: 10E861C2ED0D6F4B
MD5: C53CA5908936D412331790F4426C6C33
I’ve only been testing on low power devices (POPS/PS2, SNESC, RPi3) so no Mednafen PSX but I’d expect the benefits to be seen there, too. The game calls the BIOS (which is optimised) so the emulator or device running the game is almost irrelevant. My dump has no white (Sony logo) boot screen but does have the black (PS logo) boot screen.
@Clarkyk ah, I see. I’m not sure about how PS1 on Vita works, but it’s definitely something that should be investigated!
@Tyrr64 mine is the one you found in the wild. I’d be interested to see how yours differs? Apart from the extra logo boot screen.
@Kondorito some that come to mind: Panekit, Kero Kero King, Ridge Racer, Pepsiman, will think of some more I saw good improvements in. (not every game will see improvements)
The only graphical differences I have found is that they seem to be rendered more quickly. I’ll be doing some benchmarking soon, will publish the results here.
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I’ve been trying to find a match for your MD5 and the only reference I could find is here: https://pc12.5ch.net/test/read.cgi/software/1252720638/l50
Which appears to be: System ROM version 4.5 05/25/00 J
Update: and after a bit of digging I’ve also seen it refered to as a custom POPS BIOS, so I wonder if it has been modifed to eek out a bit more performance?
Hi,
I’ve also dumped my BIOS.
When starting BIOS Dumper 2.6, it gives the following info : Region : NTSC J BIOS version : 4.5 CRC32 : 5660F34F Date : 05/25/00
But when I dump the 5 parts, convert VMR to MCR and merge them I get the following .bin :
SCPHXXXX.bin CRC32 cc82b93b MD5 32c04484c234fd09d79625e9fe2ec232 SHA-1 b8c96eefcaedd3f8ae2a58d71671364703caaa25 Size 524288
Issue solved ! I discovered that tool VMP2MCR (Windows) was the faulty part. Basically, if after converting the first part, you open the part 2 and click convert, the part2 input file was not loaded and part1 was still converted (into part 2). So the end-result was the 5 parts 1 were merged together. The solution was to close VMP2MCR after a part was converted and the reopen the application to convert the next part. Now I get the proper CRC32 !
So cc82b93b corresponds to the merge of 5 x part1 and 5660f34f is the proper CRC32.
@Tyrr64 I think you faced the same issue as me as you have the exact same wrong CRC32.
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No one is asking the important questions here lol
Is this BIOS region free, or do 3 separate versions exist? I mean, we need all 3 to get the proper boot screens with “SCEA”, “SCEE”, and “SCEJ” under the PSX logo using current BIOS. If this “is” region free, does auto region detect function, or do we have to manually set it, or (god forbid) are we stuck with it claiming to be from a singular region despite the games own?
With this BIOS, first two screens are just skipped. You can just hear the sound from the second screen. BIOS Dump 2.6 identified the BIOS as a NTSC-J BIOS. My PSP is à European one. I used it to run a PAL game on Mednafen. So I think it’s region free. I just copied the file three times in « system » folder and renamed it scph5500.bin, scph5501.bin and scph5502.bin
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Yes, it is region free.
Wow, very interesting. Might look into this. Any ideas if this is possible on a hacked PS Vita?
“This”? Can you be more specific?
Sure, is dumping the PSX BIOS from a hacked PSP also possible on a hacked PS Vita?
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Is there any way of going about tweaking a bios like this one to imorove performance?
I can actually confirm you can also dump this using a hacked PS Vita with the use of Adrenaline. I went ahead and tested it out today and it works brilliantly. Thanks for bringing this to my attention 
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