Playing backup PSX ISOs on a PSX

Well for the old grey PS1 you can use the swap trick!

This takes practice, and can be pretty annoying, but it's useful if you don't want to risk chipping you PS, or are too cheap to do so.

Note: 1x and 2x refer to the CD motor speed (single speed and double speed respectively)

First of all, open up your PSX. On the top right, you should see a small button. This is the lid sensor. You will need something to hold it down, so that the PS thinks the lid is closed. Jamming a pen between the lid and button, or a piece of tape should work fine.

Watch a few of your games boot up with the lid open and you can easily see and hear the "gear changes". Insert a real PS game and quickly swap with copied game when the motor changes to 2x. If you did it right the Playstation screen will go black. If it goes black and theres no playstation logo, just scrambled words on the bottom, it means you burned the game wrong and it won't work at all. Watch and listen to the CD motor. It will slow down and then speed back up to 2x. After a few seconds, the CD motor will slow down again. Replace with your regular PS1 game. After another half second or so, the game will speed up again. Quickly put back the copied game. If you did it and the screen already went black, don't worry, give it a few seconds and it should still load.

You could install a mod chip. Or use an external mod thing with the serial port. There is also a "boot disc" which is what I have... It seems to be the safeist and most afficint!

Heres some more info on the pretections of the PS1!

Heres some info on the psx Protections

PSX CD Protections

There are two different copy protections within the Playstation hardware

Bad Blocks
The original PSX CD's are created with special recorders which are able to create bad blocks (segments of data on the CD which have been marked as invalid). These blocks normally are not wanted because any data that is located in a bad block is lost. Because of this, nearly all consumer CD recorders are designed to correct bad blocks when they read them before writing them to new CD's. Unless you work with Sony's special development recorders, (These recorders are only leased to companies that have a interest in keeping the protection intact, they are NOT available to end-users).

Country-Code Lockout
This protection prevents games from certain regions (US, JAP & PAL) to be played on playstations from a different region.
The Country-Code Lockout protection compares the first 5 sectors on a CD with the PSX Country-Code. If these codes match the game will continue. This protection is used to discourage importing games. Then using the below methods for copying WILL allow you to fully copy all data successfully onto a blank Cdr.
Usually the current available CD-R software is not able, using the default settings, to make a working backup.

To be able to play PSX backups the PSX needs to me changed so it will by-pass these protections. There are three ways to do this:

Using the Swap-Trick by first booting with an original PSX CD and then replacing it with the backup. This ONLY works in the earlier versions of the Playstation.

Install a MODified Boot Chip (ModChip) inside the Playstation (this can only be done by an experienced technician). The ModChip is a small electronic integrated circuit that "tricks" the PlayStation so it thinks the inserted CD contains the right Country-Code & Bad Blocks.

Use a boot disk

Use a Cardridge (like the Game Enhancer) which plugs into the expansion slot. The advantage of this cartridge is that no modifications needs to be performed on the inside of the Playstation and it leaves the PSX warranty intact.

Advanced: Details on the actual Bad Blocks: (Written by Icepic)

Sectors 12 through 15 contain a zeroised EDC/ECC checksum (impossible) so if the PSX reads and doesn't see an invalid EDC/ECC then it knows that the CD in the drive is a copy. (The EDC is simply a CRC type hash that is used as a checksum to determine if the sector was read correctly. The ECC is used to recreate the sector data). The entire range of sectors is written in a RAW format (2352 bytes) and is completely zeroed, even the XA sub-header and EDC/ECC are zeroed. When it is copied on a CD-R, these sectors are exact, except for the EDC/ECC code that is (correctly) written as 0x3F13B0BC.

With a modified bios is should be possible to make an exact backup without the need to modify the Playstation. This way it would not automatically 'correct' what it thinks to be corrupt sectors with invalid EDC/ECC codes and using a copy method of writing the first track in RAW mode (2352 byte sectors, CD-DA) and then force the table of contents to report the track as a CD-XA track.



PSX CD Layout Example
Blocks Description
000000-000015 Data track boot blocks (see NOTE 1)
000016-024520 Data track program area (see NOTE 2)
024521-024670 Postgap for data track (see NOTE 3)
024671-024820 Pregap for first audio track (see NOTE 4)
024821-048326 Audio track #1
048327-048476 Pregap for second audio track (see NOTE 5)
048477-072485 Audio track #2
.
.
.
191281-191430 Pregap for ninth audio track
191431-214349 Audio track #9
214350-?????? Leadout track (see NOTE 6)



NOTE 1: The first sixteen blocks of a PSX disc are the "boot" blocks.
They contain some territory information, but it is not known if this is the actual data that is used by the "territory lockout" code.
NOTE 2: The rest of the data track is where the actual program (game) is stored. The track is encoded in CDROM-XA format using both Form-1 and Form-2 sectors. The file system is in ISO9660 format.
NOTE 3: When any data track is followed by an audio track, it must
end with a postgap of at least 150 sectors. On all of the PSX discs that have been analyzed, this postgap is comprised of 150 sectors of zeroed data. The purpose of the postgap is to provide a "buffer zone" between the real data in the track and the subsequent audio track. This buffer is used because some CD readers can't read the last few blocks of a track if they are followed by audio sectors.
NOTE 4: When an audio track follows a data track, it must start with
a pregap of at least 150 sectors. On the PSX discs that were analyzed, pregaps of both 150 (2 seconds) and 300 sectors (4 seconds) were seen. This pregap serves the same purpose as the data postgap... to physically separate the data and audio sectors to avoid reading errors (data and
audio sectors are usually read with separate commands and each command can only read a specific sector type).
NOTE 5: The pre-gap for all audio tracks after track #1 seems to be
either 0 or 150 sectors for all PSX discs. PSXCOPY.EXE will copy these gaps, but it doesn't bother to encode them as gaps in the subcode.
NOTE 6: The LEADOUT track is written by the recorder automatically
(except for the Philips) and is not under user control. It is not
possible to read this area of the disc with a normal CDROM reader or recorder.

Hope this helps!
The Rom Master

 

how old does your psx have to be to use the swap trick, because i have the second version of the old grey one would it still work.

 

Probably, there's only one way to find out!

 

Hi Rom Master, Thanks for the tips,
My psone is model SCPH 7502 and I managed to get an ff tactics iso running using the swap trick (annoying the first
5 attempts but felt good when it worked!),
But it has a high tendency to freeze or take an obscenely long time loading between screens
and my poor heart just can't take it! (just...a...little...longer...to..save...point...no....frozen...shit!)
Any advice to stop it freezing?

Also, what can I program can I use to put the iso's on cd's?
I used sly soft clone cd for ff tactics but it doesn't work for xenogears coz it won't write it as a game cd but
as a dvd (the game cd option doesn't come up even though its an iso image)
Thanks.

 

For fixing the freezing, you should try different CD's or burning options. I use the Verbatim brand. Clone CD should work fine. Other famous burning programs for the PSX are: Nero, Alcohol 120% and CDRWIN.

I wish you the best of luck! Also remember, the PSX is very well emulated on the PC. So if you can't get a modchip or use the swap trick. You should be fine emulating it, even on a low-end PC!

 

hey guys im new to this,,
i know that u can play a rom using an emulator (well thats basically all i know)
But what exactly is a iso ??? ??? ???
do u have to burn it on a cd and then try it out on a modified psx orcan u just use it on a psx emulator???? ??? ???

 

Hi ive been trying to burn a backup copy of abe's oddysee for ages now. I have a chiped psx and im burning at 1x speed with clonecd using verbatim cd-rs but when i go to play the new disc it boots up but where it should show the playstation logo it just has a black screen with playstion writen in the centre and won't go any ferther. Ive tried several time with different programs and at varying speeds but all produce exactly the same result, is there anything im doing seriously wrong or is it simply that its a bad image to begin with.

thanx in adavance ali