Mayumi v2.1 chip install (16F84-04/P) - PS1 SCPH-1001

PSX is little endian - but that boot ROM is installed in 8 bit mode. I guess it needs to be programmed little endian too, but the datasheet doesn't seem to explicitly specify which byte is output when A-1 is low. I'm guessing it's the low byte (DQ0-DQ7) so that would make it little endian too.

 

Watching this thread with great interest, as I'm looking to have Bad_Ad do me up a Mayumi for a SCPH-1000. Or is the 1000 easier than the 1001?

 

1000 is the same as the 1001. I had no idea the late 1000's had the bios with the protection in it though, i thought that was 3000 and up

 

They are very similar - the basic difference is that with the SCPH-1000 you run the risk of getting one of the later ones with the territory check in the BIOS, and with the SCPH-1001 you have a risk of getting one with a PU-8 board that only supports partial stealth with the Mayumi code. If you can get a SCPH-1001 that you know has the PU-7, that's probably the best option.

There is also an early PU-8 variant that has the old 80-pin mechacon and 40 pin boot ROM - I've only ever seen them in Japanese machines, but I would guess that at least some SCPH-1001s have them too - and that board should work using the Mayumi PU-7 mode, since it has the same mechacon.

 

Mine's a Japanese model, are the odds good?

 

The ones with the territory check are fairly unusual in HK - although it's possible that the machines here are skewed towards the earlier versions, since the PSX was extremely popular just after it came out.

All I can tell you for sure is that the boot ROM marked

(C)SONY COMPUTER
ENTERTAINMENT INC.
RS534340F 1002
5CF 7D

Does not have a territory lockout in it - although interestingly it only displays the license screen with a NTSC:J disc (either original or copied).

 

The license screen being the video before the game starts with the PS1 logo? I like that thing, you're saying I won't get that if I run an NTSC-U game on it?

 

Seems like it - I just tried it with 6 different discs - one original and one copy from NTSC:J NTSC:U/C and PAL

The NTSC:J discs (original and copy) displayed the license screen, but the NTSC:U/C and PAL discs didn't - they just went straight from the white "Sony Computer Entertainment" screen to the game, although the actual boot time seemed about the same.

Just tried the extracted BIOS in NO$PSX, and it's the same - NTSC:J disc images give you the license screen, others don't....

 

Hmmm, is there a solution to this? Like, can you swap the BIOS for a different one?

 

Not sure - I would guess that the SCPH-1001 BIOS should work since the hardware is very similar, but I've never seen a V1.x BIOS in a US machine, they have all been V2.x or later so I can't be 100% sure - and I don't have a SCPH-1001 here to play with.

 

Hmmm, what about something similar to the region-free Dreamcast/Saturn BIOS swap? Like, swapping the BIOS chip for a custom one.

 

I guess you could do that - but as far as I know nobody has. If I had an SCPH-1001 here, I would swap the BIOS over, since that's a quick and easy thing to do with a hot air station, but I don't - and I also don't have a suitable 4mbit flash to hand.

 

This might be more of a question for someone like Bad_Ad, but would it be possible to burn a new BIOS chip that would display the PS1 logo for all regions?

 

This is already mentioned in this thread, see post 19

 

This is not quite the same thing - this is about the black "Licensed by Sony Computer Entertainment" screen that comes up during the boot process - on that original SCPH-1000 BIOS it's only shown when you boot a Japanese disc and is suppressed when booting a NTSC:U/C or PAL disc, although the game will still boot (it just goes directly from the white logo screen to the game). This is just on the very early (CRC 0x3b601fc8) V1.0 BIOS - the next V1.1 version (CRC 0x3539def6) will just dump you to the menu screen if the territory data is wrong.

The question was if an SCPH-1001 BIOS (which does display the territory information for all discs) would work - but it's hard to tell without testing it because all the ones I've seen have been v2.x and hence newer than the ones in the Japanese SCPH 1000

 

Its more that one can be burned and tested - as you dont have one to check and neither do i.

It should ​work, but its going to need testing

 

Hmmm, so you think it would be do-able? As TriMesh said, the early SCPH-1000 BIOS will boot all games, so it's functional, but it would be nice if all disks did the cool boot animation.

 

Okay, I've got the new PS1 (it has the disk read issue, but that's a problem that will be resolved when I can get a PSONE to gut ) and I'm looking to get it all mod chipped. Bad_Ad, how did you go with the chip for harry1038? You seemed unsure about the chip's programming last I saw. Is everything all sorted out and working?

 

Wanting to know endianness (so I didnt need to check) isnt being unsure.

But still waiting for the parts to arrive to me

 

Ah, ok. So you're all rearing to go once the parts arrive then? Are they still £2.50 plus £2 for international shipping?