[DEV] - Flash Boot Rom PS1
-
Xrider Verified
- Curious PSXDEV User
- Posts: 31
- Joined: Jan 04, 2019
- I am a: Hardware Dev
- PlayStation Model: SCPH-5502
- Contact:
[DEV] - Flash Boot Rom PS1
Hello,
I just told you about my project PS1 bios exchange.
I took a step in PCB design and physical testing on a PU-20 (Motherboard SCPH-7002)
The tests are conclusants.
Here are some photos:
Mounting:
Bios No $ Psx
Bios PSone (SCPH-100) JAP
Yes this last model will be mounted piggyback, the function "Dual bios" will be insured: 3207319737:
it's as big as a 50 cent coin: icon_study:
Some pictures :
Questions answers
What is the purpose of using a custom bios or Dev official?
=> Several reasons:
1 - PS1 jap have extra protection in their bios. With a bios EU or US, finished the zoning and hello the freezone (modchip for the region of Mechacon necessary)
2 - The bios No $ psx (Custom Bios) allows the boot of backups without chip, has advanced functions (Thanks No $ Cash)
3 - To make the dev or a future Bios Custom
4 - Just for fun, change the appearance of the original menu and others ...
To be reprogrammable without desoldering the Flash bios of the motherboard, I need help.
Would it be possible for one of you to modify a flasheur action replay by CD to reflash the eeprom?
I confirm, theoretically the pcb is compatible for re-programming via a CD.
Extract from the doc of the flash memory used on the circuit:
"devices write with a 2.7-3.6V power supply"
In other words, the address bus A19 which is not used on the BOOT ROM of the PS1 (PIN1 of the ROM mask boot) could be used to put the chip in writing state by putting it in the HIGH state on the PIN WE.
Thanks for your help
I just told you about my project PS1 bios exchange.
I took a step in PCB design and physical testing on a PU-20 (Motherboard SCPH-7002)
The tests are conclusants.
Here are some photos:
Mounting:
Bios No $ Psx
Bios PSone (SCPH-100) JAP
Yes this last model will be mounted piggyback, the function "Dual bios" will be insured: 3207319737:
it's as big as a 50 cent coin: icon_study:
Some pictures :
Questions answers
What is the purpose of using a custom bios or Dev official?
=> Several reasons:
1 - PS1 jap have extra protection in their bios. With a bios EU or US, finished the zoning and hello the freezone (modchip for the region of Mechacon necessary)
2 - The bios No $ psx (Custom Bios) allows the boot of backups without chip, has advanced functions (Thanks No $ Cash)
3 - To make the dev or a future Bios Custom
4 - Just for fun, change the appearance of the original menu and others ...
To be reprogrammable without desoldering the Flash bios of the motherboard, I need help.
Would it be possible for one of you to modify a flasheur action replay by CD to reflash the eeprom?
I confirm, theoretically the pcb is compatible for re-programming via a CD.
Extract from the doc of the flash memory used on the circuit:
"devices write with a 2.7-3.6V power supply"
In other words, the address bus A19 which is not used on the BOOT ROM of the PS1 (PIN1 of the ROM mask boot) could be used to put the chip in writing state by putting it in the HIGH state on the PIN WE.
Thanks for your help
Last edited by Xrider on September 17th, 2022, 6:25 pm, edited 2 times in total.
The code to write to flash is fairly easy, you are just putting the commands to the correct addresses. You may be able to write to it by pulling WE low when flashing and wire everything else exactly the same, omitting the A19 pin.
The BIOS sits at 0xbfc00000 to 0xbfffffff so we could look at writing to those addresses rather than the usual extension ROM area. I have no idea what would happen if you try and write to the BIOS area in memory when it is in fact writable, and also given that the BIOS is in use at the time you are writing to it may cause issues..
Ideally though, I would like a PSone compatible version that allows it to be hooked up as an extension ROM using CE1 etc (ie AR/XP) rather than to replace the BIOS.
Good luck with your project, and if I could register my interest to possibly purchase a 2 units from you with respect to supporting it in NXFLASH?
Just be careful what flash part you choose to use.. as some are a little trickier to support. Personally I would recommend using an SST29EE020 as they are still easy to obtain in TSOP package and are easy to support code wise.
Feel free to drop me a PM if I can help. I was looking at your forum but unfortunately my French is appalling.
The BIOS sits at 0xbfc00000 to 0xbfffffff so we could look at writing to those addresses rather than the usual extension ROM area. I have no idea what would happen if you try and write to the BIOS area in memory when it is in fact writable, and also given that the BIOS is in use at the time you are writing to it may cause issues..
Ideally though, I would like a PSone compatible version that allows it to be hooked up as an extension ROM using CE1 etc (ie AR/XP) rather than to replace the BIOS.
Good luck with your project, and if I could register my interest to possibly purchase a 2 units from you with respect to supporting it in NXFLASH?
Just be careful what flash part you choose to use.. as some are a little trickier to support. Personally I would recommend using an SST29EE020 as they are still easy to obtain in TSOP package and are easy to support code wise.
Feel free to drop me a PM if I can help. I was looking at your forum but unfortunately my French is appalling.
-
Xrider Verified
- Curious PSXDEV User
- Posts: 31
- Joined: Jan 04, 2019
- I am a: Hardware Dev
- PlayStation Model: SCPH-5502
- Contact:
Hello danhans42.
Thank you for your interest on my project.
It is with pleasure that I will sell you two units at a reduced price if you can update NxFlash to be able to flash them.
I wait my first PCB, it's will come in couple of weeks.
I planned to use 4Megabit flash rom, the SST39VF040 TSOP.
It's very similar of SST29EE020 for flash them
All bios will be go inside (No SCPH-5903 )
Xrider
Thank you for your interest on my project.
It is with pleasure that I will sell you two units at a reduced price if you can update NxFlash to be able to flash them.
I wait my first PCB, it's will come in couple of weeks.
Ideally though, I would like a PSone compatible version that allows it to be hooked up as an extension ROM using CE1 etc (ie AR/XP) rather than to replace the BIOS.
Yes, but SST29EE020 is only 2 Megabit. it's ok for AR/XP and No$Cash rom, but it's to small for genuine BIOS (for change genuine bios JAP to other country for freezone with modchip)Personally I would recommend using an SST29EE020 as they are still easy to obtain in TSOP package and are easy to support code wise.
I planned to use 4Megabit flash rom, the SST39VF040 TSOP.
It's very similar of SST29EE020 for flash them
All bios will be go inside (No SCPH-5903 )
I will make more test for put the bios AR/XP, but with no GAL/PAL, probably doesn't work with no modification of there romIdeally though, I would like a PSone compatible version that allows it to be hooked up as an extension ROM using CE1 etc (ie AR/XP) rather than to replace the BIOS..
No problem, i post the evolution here for you and again, thanks for your helpFeel free to drop me a PM if I can help. I was looking at your forum but unfortunately my French is appalling.
Xrider
Hi,
The ST29EE and ST39 series are programmed differently. The 29 series is written as words (128/256byte)whereas the 39series series is written as a single byte so the flash algo will be slightly different.
The write commands are pretty much JEDEC standard, its just the order in which they work. If you look through the datasheets its quite easy to see in the xflash source code how it works.
I am currently looking to support the SST39 series in NXFLASH but the work is ongoing.
If you can let me know when you have the boards I will quite happily buy a few.. I have some ST39 in hand in TSOP32 but they are 256k so would also need the chips.
Great project mind you. Would love to see some proper BIOS mods for the original BIOS.
The ST29EE and ST39 series are programmed differently. The 29 series is written as words (128/256byte)whereas the 39series series is written as a single byte so the flash algo will be slightly different.
The write commands are pretty much JEDEC standard, its just the order in which they work. If you look through the datasheets its quite easy to see in the xflash source code how it works.
I am currently looking to support the SST39 series in NXFLASH but the work is ongoing.
If you can let me know when you have the boards I will quite happily buy a few.. I have some ST39 in hand in TSOP32 but they are 256k so would also need the chips.
Great project mind you. Would love to see some proper BIOS mods for the original BIOS.
Can't you just use a bigger flash rom? E.g have room for 2 in your flash and a way to set the "active" one. Then when flashing only allow flashing the non active/loaded bios?
-
Xrider Verified
- Curious PSXDEV User
- Posts: 31
- Joined: Jan 04, 2019
- I am a: Hardware Dev
- PlayStation Model: SCPH-5502
- Contact:
danhans42 When I have received the circuits, you will be the first to know.danhans42 wrote:If you can let me know when you have the boards I will quite happily buy a few.. I have some ST39 in hand in TSOP32 but they are 256k so would also need the chips.
do you want a totally assembled card with a TSOP SST39VF040?
For me it's the best eeprom available on the market for this mod (512Ko)
Samedanhans42 wrote:Great project mind you. Would love to see some proper BIOS mods for the original BIOS.
You guys might wanna look here... Bios flasher supporting the 39F series.
https://www.obscuregamers.com/threads/bios-flasher.771/
https://www.obscuregamers.com/threads/bios-flasher.771/
Hi xrider.
Great work. Look forward to testing! If you can drop me a PM with the details and I can send you payment for the module, and see if we can get it flashed in the console using the software from obscuregamers in the link.
Great work. Look forward to testing! If you can drop me a PM with the details and I can send you payment for the module, and see if we can get it flashed in the console using the software from obscuregamers in the link.
I'm also interested in a populated board!
It'd be best with a 512kB chip, but 256kB is workable as well.
The No$Cash BIOS is pretty well compatible, but only if the Memory Card fast access option is turned fully off*.
I would want to use this 256k BIOS in my main machine, just because of the novelty ;p
*Any speedup of Memory Card operations is unfortunately breaking (even corrupting) saves.
For that reason it would be best to patch the No$Cash BIOS default parameters, so the speedup option defaults to off.
The defaults surely are a byte somewhere in the rom image.
If it isn't patched, users can still disable the option.
In that case the option will be saved onto Memory Card 0, and then this Memory Card needs to be present at boot time.
It'd be best with a 512kB chip, but 256kB is workable as well.
The No$Cash BIOS is pretty well compatible, but only if the Memory Card fast access option is turned fully off*.
I would want to use this 256k BIOS in my main machine, just because of the novelty ;p
*Any speedup of Memory Card operations is unfortunately breaking (even corrupting) saves.
For that reason it would be best to patch the No$Cash BIOS default parameters, so the speedup option defaults to off.
The defaults surely are a byte somewhere in the rom image.
If it isn't patched, users can still disable the option.
In that case the option will be saved onto Memory Card 0, and then this Memory Card needs to be present at boot time.
Sure, and thanks
-
LameGuy64 Verified
- Psy-Q Enthusiast
- Posts: 388
- Joined: Apr 10, 2013
- I am a: Hobbyist Game Developer
- Motto: Commercial or not, play it!
- PlayStation Model: H2000/7000
- Location: Philippines
- Contact:
That's a pretty sick BIOS ROM mod kit Xrider! I imagine this would be most useful in turning PsOnes into compact development units by storing a serial loader or a customized BIOS menu with serial loading capabilities into BIOS ROM.
Please don't forget to include my name if you share my work around. Credit where it is due.
Dev. Console: SCPH-7000 with SCPH-7501 ROM, MM3, PAL color fix, Direct AV ports, DB-9 port for Serial I/O, and a Xplorer FX with Caetla 0.35.
DTL-H2000 PC: Dell Optiplex GX110, Windows 98SE & Windows XP, Pentium III 933MHz, 384MB SDRAM, ATI Radeon 7000 VE 64MB, Soundblaster Audigy, 40GB Seagate HDD, Hitachi Lite-on CD-RW Drive, ZIP 250 and 3.5" Floppy.
Dev. Console: SCPH-7000 with SCPH-7501 ROM, MM3, PAL color fix, Direct AV ports, DB-9 port for Serial I/O, and a Xplorer FX with Caetla 0.35.
DTL-H2000 PC: Dell Optiplex GX110, Windows 98SE & Windows XP, Pentium III 933MHz, 384MB SDRAM, ATI Radeon 7000 VE 64MB, Soundblaster Audigy, 40GB Seagate HDD, Hitachi Lite-on CD-RW Drive, ZIP 250 and 3.5" Floppy.
Hello, can't say that my old work will be helpfull to the @xrider or anyone else but here is the link to an old AG thread:
https://assemblergames.com/threads/ps1-bios-pcbs.68957/
Attachment shows how's it look. It's PSX-XBOO programmed (modchip is not needed but it still there, don't know why I didn't get rid of it a year ago).
Still, didn't try to reprogram my EEPROM with a modded CD that megavolt85 provide (sorry man), I were really out of console moding things for a year or more. I'm starting to getting back to it with new ideas (didn't know if they are useless or not but I'll try).
https://assemblergames.com/threads/ps1-bios-pcbs.68957/
Attachment shows how's it look. It's PSX-XBOO programmed (modchip is not needed but it still there, don't know why I didn't get rid of it a year ago).
Still, didn't try to reprogram my EEPROM with a modded CD that megavolt85 provide (sorry man), I were really out of console moding things for a year or more. I'm starting to getting back to it with new ideas (didn't know if they are useless or not but I'll try).
You do not have the required permissions to view the files attached to this post.
-
Xrider Verified
- Curious PSXDEV User
- Posts: 31
- Joined: Jan 04, 2019
- I am a: Hardware Dev
- PlayStation Model: SCPH-5502
- Contact:
Nice job Armorant,
My first revison was look like your pcb, but i would like preserve the genuine bios and add au dual bios fonction, and for that, i have make the new pcb
I use the same eeprom, the SST39VF040
My first revison was look like your pcb, but i would like preserve the genuine bios and add au dual bios fonction, and for that, i have make the new pcb
I use the same eeprom, the SST39VF040
Thanks for Your words. PCB design above (for TSOP) has the dual BIOS capability, but I tried that only once a year ago with wrong BIOS writed. I wanted to use a 1001 as device 2 (PS1 BIOS ROM) and no$cash BIOS as device 0 (expantion ROM). They won't work cause back then no$cash BIOS has no capability to work as expantion ROM. Still can't find a version of no$cash BIOS that might work as expantion ROM.
-
Squaresoft74 Verified
- /// PSXDEV | ELITE ///
- Posts: 309
- Joined: Jan 07, 2016
- PlayStation Model: SCPH-7502
- Location: France
- Contact:
There is one for Xplorer & Datel cheat devices using No$psx to create it or just get the attached file.
You do not have the required permissions to view the files attached to this post.
-
Xrider Verified
- Curious PSXDEV User
- Posts: 31
- Joined: Jan 04, 2019
- I am a: Hardware Dev
- PlayStation Model: SCPH-5502
- Contact:
I have try to burn it with expand.exe (thanks No$cash) with kHn compilation (thanks kHn) and it's work when :
WE is connected to SWRO
CE is connected to CS0.
It's work look like the Action replay.
I confirm the ID of the SST39VF040 it's "BF D7"
I think about it's possible to flash the original bios with this config, and after that we will switch the CE to CS2.
I try it a the next time
WE is connected to SWRO
CE is connected to CS0.
It's work look like the Action replay.
I confirm the ID of the SST39VF040 it's "BF D7"
I think about it's possible to flash the original bios with this config, and after that we will switch the CE to CS2.
I try it a the next time
-
- What is PSXDEV?
- Posts: 2
- Joined: Aug 07, 2019
You do not have the required permissions to view the files attached to this post.
-
Xrider Verified
- Curious PSXDEV User
- Posts: 31
- Joined: Jan 04, 2019
- I am a: Hardware Dev
- PlayStation Model: SCPH-5502
- Contact:
Thank you for your help megavolt85
I have tried it and now it recognizes my eeprom.
I tried to burn the SCPH-7002 bios.
it take a long time (30mns) to burn 512Ko.
After that, not work (CSO and CS2 swapped = same thing).
But after burned the eeprom, i have dumped the eeprom.
You can maybe debug your software with this file :
http://www.delta-island.com/dump-bios-s ... r-burn.zip
Thanks
Who is online
Users browsing this forum: No registered users and 4 guests