I don't think these are ESDI drives. I think they are standard floppy drives, with the power over the connector. Get yourself a standard floppy drive and build an adapter using a 34 pin header, a 40 pin header and some cable. Here are the apparent pinouts for the IBM model 50.
PS/2 1.44MB Floppy 40 pin pinout
Code:
Pin I/O Signal Pin I/O Signal
--- --- ------ --- --- ------
1 n/a -2nd drive 2 o -high density select
3 n/a reserved 4 n/a reserved
5 n/a ground 6 n/a reserved
7 n/a signal ground 8 i -index
9 n/a signal ground 10 o reserved
11 n/a signal ground 12 o -drive select
13 n/a ground 14 o reserved
15 n/a signal ground 16 o -motor enable
17 n/a signal ground 18 o -direction in
19 n/a signal ground 20 o -step
21 n/a signal ground 22 o -write data
23 n/a signal ground 24 o -write enable
25 n/a signal ground 26 i -track 0
27 n/a signal ground 28 i -write protect
29 n/a signal ground 30 i -read data
31 n/a signal ground 32 o -head 1 select
33 n/a signal ground 34 i -diskette change
35 n/a ground 36 n/a ground
37 n/a ground 38 o +5 VDC
39 n/a ground 40 o +12 VDC
Standard 34 pin floppy
Code:
1 Ground -- 2 /REDWC Density Select 1=Low/0=High
3 Ground -- 4 N/C Reserved
5 Ground -- 6 N/C Reserved
7 Ground -- 8 /Index 0=Index
9 Ground -- 10 /MOTEA 0=Motor Enable Drive 0
11 Ground -- 12 /DRVSB Drive Select 1
13 Ground -- 14 /DRVSB Drive Select 0
15 Ground -- 16 /MOTEB 0=Motor Enable Drive 1
17 Ground -- 18 /DIR 0=Direction Select
19 Ground -- 20 /Step 0=Head Step
21 Ground -- 22 /WDATE Write Data
23 Ground -- 24 /WGATE Floppy Write Enable, 0=Write Gate
25 Ground -- 26 /TRK00 0=Track 00
27 Ground -- 28 /WPT 0=Write Protect
29 Ground -- 30 /RDATA Read Data
31 Ground -- 32 /SIDE1 0=Head Select
33 Ground -- 34 /DSKCHG 1=Disk Change/0=Ready
Cut line 1 in the cable. Leave 35, 36 unconnected.
Use 37-40 on the PS2 to connect up a standard 4pin power connector.
see
http://www.walshcomptech.com/ohlandl/floppy/Floppy_Pinouts.html