On 1/6/14 6:52 PM, Al Kossow wrote: Al, Bitsavers does not have manuals for either the Dysan Model 450 (5 1/4" drives" or Model 850 (8" drives) online. I do have an original Model 450 manual if you need scans. (I know, I still owe you VG schematic scans.) I did put a Dysan PAT-1 Model 850 (8" drives) up on eBay yesterday in case anyone cares. No manual or accessories :(. FWIW, I have both the Accurite HRD and Dysan DDD 5 1/4" Digital Diagnostic Disks, and they don't seem to be compatible. I use QAFloppy (Diagsoft QAFE/Plus) with the Accurite HRD and it works fine. However the Dysan disk is not recognized by the software. Second, I see the PAT-1 Schematic on Bitsavers is for the PAT-1 Model 850 for 8" disks. Third, the PAT-1 box isn't directly compatible with PC floppies as the interface signals are slightly different. Works fine with the early Shugart/Tandon drives, but won't recongnize PC drives. Finally, I have maybe six or so of the Dysan DDD disks marked bad, bad side 0, or bad side 1. If someone wants to see if they can use them, let me know.