Ok, Floppy Experts...

From: Douglas H. Quebbeman <dquebbeman_at_acm.org>
Date: Sat May 4 18:09:35 2002

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
Received on Sat May 04 2002 - 18:09:35 BST