>>No SCSI devices. Any other ideas?
>>
>Then I would say that the DOS disks have to be corrupted - probably with some 6.22 files copied onto it (this was a common practice back in the DOS days) when DOS disks were THE tool to have. Sometimes files of one version got onto another. Have you tried a different set of disks? You can look at the dates of the files on the disks. I believe they started dating the files based on version with 6.00.
>
>Other than that, I dunno.

The Model 70 is a MicroChannel PC and seems to run better on IBM DOS. Any chance you have that version laying around?

HTH,