4869drve.exe PS/2 5.25" Disk Adapter/Option Driver Diskette
4869DRVR files in rar archive
   IBMDSKT5.EXE Installation Program for the 5.25-inch Diskette Device Driver
   $FDD5.SYS  DOS Diskette Device Driver
   EXT5DD.SYS - OS/2 Diskette Driver

H025731 External drive motor spins when accessing internal drive [4869 on 8580]
H037905 Intermittent 4869 Read Errors

   Exists in two versions, a 360KB (-001) and 1.2MB (-002) versions. The 360K external floppy can be used with either 5.25" diskette adapters. The 1.2MB external floppy drive is limited to the 1.2MB version of the 5.25" external floppy adapter

WBST says:
   I’ve been using an old 4869-001 (later dual 110/230V supply voltages PSU and FRU = 72X6759) with the adapter for the 1.2MB/360KB drives (I can see no reason why only the 1.2MB -002 drive is exclusively supported, as long as 360KB DS/DD media are used in the -001 drive). I’m trying to see if I can use this to bypass a P75’s failed FDC, by creating a stripped-down 360KB RefDisk to Set Config, that’s why.

The 4869-x01 has an embossed "Star" symbol in the faceplate of the drive.

 If you look at the underside you will find 4869-xxx, where 

Tony sez:
   The 1.2M drive needs a different controller than the 360K.  The 360K will work with the "bay sled" and minimal controller (and appear as the B: drive without any drivers being loaded), the 1.2M needed the more complex controller (lots of chips) and needed a driver loaded (and would appear as E:)

      The external diskette drive (4869-002) and the internal diskette drive (6451006) do not operate as the "B" drive unlike the current (360KB) Personal System/2 5.25-inch External Diskette Drive (4869-001),  This frees up the "B" slot so that it can be used for other features (refer to Product Announcement 188-148, dated September 13, 1988).  When the system is configured for the 5.25-inch diskette drive, the drive is assigned the next available drive letter.  For example, if the using system has diskette drive "A" and fixed disk drive "C", then the 5.25-inch diskette drive will be assigned as the "D" drive.

H025731 External drive motor spins when accessing internal drive

   It is normal for the 4869 external 5.25" diskette drive spindle motor to spin when the internal diskette drive is accessed on 8580 products. In fact, both spindle motors will spin when either drive is accessed. This also holds true if both drives are internal 3.5" diskette drives (three diskette drives are not supported on the system). Activating both spindle motors provides increased performance on multiple drive operations such as "DOS DISKCOPY", since motor start delays are eliminated when switching between drives. Operating both motors simultaneously will not affect device reliability.

 [Ed. This makes sense for the bare 360KB floppy controller adapter, as it is just a pass-through, and uses the planar floppy disk controller. Don't know if this applies to the 1.2MB Adapter/A. This may also apply to other PS/2s that use the Drive Connector Assembly]

H037905 Intermittent 4869 Read Errors 

Low frequency fluctuating magnetic fields generated by displays can cause read errors in the 4869. So if the 4869 -001/-002 is placed too close to a display or monitor, diagnostics and applications may fail intermittently. Try relocating the 4689 away from the display.

If diagnostics still fail on the external diskette drive, follow normal problem determination procedures.