Well, here is the pinout of the typical IBM external floppy drive (5.25) & interface: External Diskette Adapter -----------------------, unused 1 | Diskette Drive unused 2 | ,----------------------- unused 3 |----------------| 2 unused unused 4 |----------------| 4 unused | |----- alignment slot unused 5 |----------------| 6 Drive Select 4 Index 6 |<---------------| 8 Index Motor Enable C 7 |--------------->| 10 Drive Select 1 * Drive Select D 8 |--------------->| 12 Drive Select 2 * Drive Select C 9 |--------------->| 14 Drive Select 3 * Motor Enable D 10 |--------------->| 16 Motor On * Direction Select 11 |--------------->| 18 Direction Select Step 12 |--------------->| 20 Step Write Data 13 |--------------->| 22 Write Data Write Gate 14 |--------------->| 24 Write Gate Track 00 15 |<---------------| 26 Track 00 Write Protect 16 |<---------------| 28 Write Protect Read Data 17 |<---------------| 30 Read Data Head Select 18 |--------------->| 32 Head Select unused 19 |----------------| 34 unused -----------------------' `----------------------- Bottom Row Sockets 20 - 37 of the DB37S Connector are Ground Now, here is what Chris gave me earlier for the Type 9331 Model 011: External Signal Cable Connector Table 7-1. Pin Assignments for 37 Pin D Shell Cable Signal Name Signal Pin Ground Pin Reduced Write Current 2 20 Drive Select 0 8 26 Motor On (Head Load) 10 29 Direction Select 11 29 Step 12 30 Write Data 13 31 Write Gate 14 32 Side one Select 18 36 Ready 9 27 Index 6 24 Track 00 25 33 Write Project 26 34 Read Data 27 35 Diskette Change 19 37 Two Sided 7 25 8-Inch Drive Attached 5 23 5.25-Inch Drive Attached They look pretty compatible... Now, the next step would be OS support. I think I know how to make it work for an older DOS machine, but what about Windows? Anyone else done this yet? Regards, -doug q