Hi,
I have a DIY single-board computer (extensively discussed elsewhere in this forum) which runs CP/M from a CompactFlash card connected via an 8-bit IDE interface.
All works fine with the original 64MB CF card and a newer one I have for testing. I also have a 128MB CF card that I'm using to test a BIOS that provides CP/M with more drives.
Everything works fine and dandy with the 128MB CF card, until I turn the SBC off (or, more accurately, pull the USB serial connection from the PC.) When I next power up the computer, it won't load CP/M and I have to re-install (write CP/M and BIOS to sector 0 of the CF card).
A check of the code in memory shows that the last two pages (FE00-FFFF) are corrupt. The monitor ROM loads Sector 0 from CE00-FFFF, and it seems the last part of Sector 0 is getting corrupted every time the SBC loses power. This is 100% reproducible every time with the 128MB CF card (the others are fine, by the way.)
So, I guess what I'm asking is this: what failure mode would cause this behaviour in the CF card?