How to dump your CDROM BIOS (Firmware)

Members research, findings and information that can be useful towards the PlayStation 1.
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Curious PSXDEV User
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Joined: Jan 04, 2019
I am a: Hardware Dev
PlayStation Model: SCPH-5502

Post by Xrider » June 12th, 2021, 5:14 pm

Charles MacDonald wrote: May 31st, 2014, 10:38 am If you are using a TTL RS-232 to USB converter (e.g. DLP-USB232R, FTDI UM232H, etc. which appears as a virtual COM port) to dump the CD BIOS, I've developed a command-line program that uploads the dumping program and saves the results. The source code and a Windows binary are available here:

I've tried to make it easy to use at every step, so troubleshooting problems should be simple.

For dumping I did some things slightly differently; I connected 7.5V to pin 31 and 3.5V to pin 17 using a 10K-ohm resistor in series to limit current into these pins, instead of a direct connection. It's not strictly necessary however. Also on this particular PU-8 board there is a 4.7K ohm pull-up resistor to 3.6V on pin 31 on the component side of the board that should be removed when dumping. On the solder side it can be seen as a via prior to the test point.

For the RS-232 to USB converters mentioned, what worked for me was to configure them as being bus-powered (using 5V from the USB cable), and connecting the VCCIO pin to the PSX 3.6V supply and the ground pins to the PSX ground. There are probably other ways to power the converters that work as well.

Someone have this software ? the link is dead.

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PlayStation Model: H2000/5502
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Post by Shadow » July 28th, 2021, 4:36 pm

You'll have to contact the original author somehow to get a copy.
I think this is his new site:
Development Console: SCPH-5502 with 8MB RAM, MM3 Modchip, PAL 60 Colour Modification (for NTSC), PSIO Switch Board, DB-9 breakout headers for both RGB and Serial output and an Xplorer with CAETLA 0.34.

PlayStation Development PC: Windows 98 SE, Pentium 3 at 400MHz, 128MB SDRAM, DTL-H2000, DTL-H2010, DTL-H201A, DTL-S2020 (with 4GB SCSI-2 HDD), 21" Sony G420, CD-R burner, 3.25" and 5.25" Floppy Diskette Drives, ZIP 100 Diskette Drive and an IBM Model M keyboard.

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Post by MottZilla » May 1st, 2022, 5:52 am

I can confirm that SC430911PB is vC1 24 Jul 1995. I've been trying to find a unit with the earlier vC1 and I came across this unit and read the part number as it wasn't working. When I saw a table on the 1st page with this part number I did my best to get the system working and when it did I ran my own program that pulled the date and version.

The console it came from had a Sony refurbished sticker on it and it was a model SCPH-1001. It was a PU-8 motherboard. I didn't take any pictures though sorry.

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