DOS disk read test program

On Mon, 21 Jul 2014, Liam Proven wrote: With my current error rate (unrefreshed dynamic wetware RAM), I am hesitant to say that anybody is "wrong", but the XT/5160 controller very definitely supported 2 hard^H^H^H^H fixed drives, and I often used 2 hard drives on XT; and I think that that was with 2.00, 2.10, 2.11, 3.00. BTW, using other than 10M called for soldering jumpers (or a 4 position DIP switch). There were two bits for each drive, and I think that they may have been 5M, 10M, 16M, 26M. 5170 stored har drive parameters in CMOS, which is another thread. I heard that the controllers could be modified to support more than one controller, but I never tried. 3.10 added support for the "Network Redirector", and enabling MSCDEX to present a CD-ROM (>650M!) as if it were a resource on a network. Trying to CHKDSK a CD-ROM: "YOU CAN NOT CHKDSK A NETWORK DRIVE" I heard that the same technique could be used for big hard drives, with a lotta work, but I never tried. LASTDRIVE was needed if you wanted to go past 5? drives (4 floppies, 2 hard drives, and a CD-ROM) also 720K floppies (also present in some OEM versions of 2.11) Early 5170s needed DRIVER.SYS or DRIVPARM for 720K DRIVPARM was present in MS-DOS 3.20, and present but undocumented in PC-DOS 3.20. BUT, my real OEM 5170 BIOS's would give "UNRECOGNIZED CONFIG.SYS COMMAND" when using either MS-DOS OR PC-DOS DRIVPARM, but aftermarket BIOS worked with either! That never made sense to me. Are you sure that multiple partitions weren't present in prior versions? Are you sure that it wasn't FOUR? While probably the most POPULAR, Compaq was not unique for 3.31.