problems with modified Kernel in PSX version.

[TEK]

I've searched high and low on the site, but there's such mountains of technical jargon that I can't seem to find the answer I need, though it's probably here somewhere.

I've created a modified KERNEL.BIN using wallmarket. I extracted the original .bin from an ISO of the PSX game image using Magic ISO (a registered version that has no restrictions on file size) but when I put the modified Kernel back into the folder and save the ISO it no longer works in ePSXe. if I use the same program to save a duplicate of the ISO unaltered it does work, just not if I've injected the new Kernel.

I'm guessing this an obvious mistake to all you learned folk, and has something to do with the files being expected to be in an exact place within the ISO image or something. but I can't for the life of me find a utility or program that's intended to inject that kernel into the ISO without making a mess of things.

my eternal gratitude to anyone who can help me out here.

[Bosola]

Magic ISO is probably trying to create a disc image with a CD-ROM filesystem. This won't work with a PSX disc; it has its own filesystem, and a different way of arranging data into sectors. Use CD Mage beta instead, working with the disc in 'Mode2' format.

[TEK]

okay, having installed CDMage I can see that this is the case, the versions that I saved with my modifications are showing up as Mode1 while the original ISOs are showing up as mode2.

but I'm not finding anyway in CDmage to edit the mode2 images, or to convert my mode1 images to mode2.

so while this program confirms what the problem is with my previous software, I'm still not seeing a way to actually inject the modified kernel into the ISO. am I missing something?

thanks for the help so far, but I'm gonna need a little more assistance if I'm gonna make this work.

EDIT: Okay I was able to import the file when I actually got the correct version of CDMage, however it tells me that it has to truncate the import file because it's too large. all I did was edit the initial equipment as a test to see if I could make it work. is this file truncation going to cause me problems down the line? what if I do more extensive modifications?

[Bosola]

okay, having installed CDMage I can see that this is the case, the versions that I saved with my modifications are showing up as Mode1 while the original ISOs are showing up as mode2.

but I'm not finding anyway in CDmage to edit the mode2 images, or to convert my mode1 images to mode2.

Yeah, you'd probably have to rebuild the ISO if you wanted to make your Mode1 images into Mode2 ISOs. Not really worth it.

EDIT: Okay I was able to import the file when I actually got the correct version of CDMage, however it tells me that it has to truncate the import file because it's too large. all I did was edit the initial equipment as a test to see if I could make it work. is this file truncation going to cause me problems down the line? what if I do more extensive modifications?

Yes. You've had to cut off the end of the file to fit it into the limited space it was given on the CD. That's going to cause problems.

There are practical limits on the size of a PSX kernel; you can get around the disc space issues without much trouble, but because the whole KERNEL is loaded into the PSX RAM before its contents are extracted, and it's only allocated a limited amount of memory, you've a practical maximum of around 25K.

If you want to work around this, remove stuff that's unused on the disc you're working on - like strings for equipment names, for example. This will free up space for your new content.