I felt sorry for this chap - I culled this entry off alt.video.dvd.tech:

i know in advance how stupid this was..
Ok, i just did the dumbest thing i could possibly do updating the firmware on this dvd-rom. First off it is a pioneer 500m. I have no floppy drive on this box so I burned a dos bootable cd and put it in the pioneer drive and rebooted. I put the firmware update on the bootable cd also. So when i booted to dos, i ran the firmware update. It deleted the old firmware fine, and then just froze, since then it could not read the cd in the drive, since no firmware. So right now I have a dvd drive that has no firmware and I can not boot with it installed on my machine. If i try, the light stays on on the drive and the machine hangs 'detecting IDE devices..'

I am not able to get into my bios set up or anything. I have no idea how to fix this. Any ideas?

I hope I don't make too many mistakes as fundemental as this!