davidsen@steinmetz.steinmetz.UUCP (William E. Davidsen Jr) (10/09/87)
In article <811@cup.portal.com> Isaac_K_Rabinovitch@cup.portal.com writes: |Has anyone heard of an AT clone blowing up with a "PARITY ERROR" without |there being an actual hardware problem? Can this result from software |accessing the hardware in a flaky manner? I'd appreciate hearing from |people who have had similar problems. I also appreciate hearing from |people who think that the idea is preposterous. Because Fastback beats the hardware in the memory/DMA areas hard (but within specs, at least for IBM) some marginal systems have problems with the program. Fastback runs the floppy by using an alternate DMA channel to write the floppy while DOS uses the hard disk and primary DMA channel. Many people try to run this on a clone which is either incompatible or just plain cheap, and then blame Fastback for problems. The common problems include parity errors (I think caused by missed refresh during DMA), garbled data, and failure to write certain floppy disks. I have a cheap brand of 1200k floppy which won't Fastback at 16 MHz, but will at 8. I don't use them for anything critical. I'm told that some BIOS ROMs will not correctly handle any other process doing interrupt driven i/o while DOS is running. This, too, sometimes results in a software generated parity error. Systems which seem to have problems include the Zenith Z-248 and ATT6300 (and I believe 6300+). Corrective action may be taken by slowing the system down (if available), or using some of the install modes, such as /SLOW. I have run Fastback on a number of IBM and good clone PCs and have been very pleased. I don't card how reliable a backup is, or how great the interface is, if a backup takes a long time the average user won't use it. -- bill davidsen (wedu@ge-crd.arpa) {uunet | philabs | seismo}!steinmetz!crdos1!davidsen "Stupidity, like virtue, is its own reward" -me