zeno@athena.mit.edu (R. Duffy) (05/28/91)
We have several AT&T PC 6300's, on which I've been installing Fastback Plus. Until now, they all passed the highest speed DMA controller test (for I/O to the standard floppy drive, 5.25" DD). But one of them is reliably passing the low-speed test and FAILING the medium-speed. These units were acquired en masse and should have identical hardware. What can I conclude about the black-sheep machine? A problem on the DMA chip, or a less-than-optimum drive? We did a massive backup from a different machine, deposited the files onto the bad machine, then backed up from the latter (*slowly* -- since Fastback was using the low DMA speed) and compared to the original files on the different machine, and all was fine. But this is the ONLY one out of quite a few which has not passed the high-speed test. Ideas? Email preferred. Thanks! Richard Duffy zeno@athena.mit.edu +1 617 253 4045