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IBM 5150  -  Floppy Drive Support


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Cable and Termination

• Use the cable shown at here.

• For 5.25" drives, terminate as appropriate, per the diagram at here.



5.25" 360K floppy drives

DOS:  DOS 2.0 or later  (2.0 introduced DOS support for 360K floppies).
BIOS:  The IBM BIOS (all three revisions) on the IBM 5150 motherboard has full support for 360K drives/floppies.
Hardware:  The floppy controller (photo) that IBM supplied in the IBM 5150 supports 360K drives.



5.25" 1.2M floppy drives

DOS:  DOS 3.0 or later  (3.0 introduced DOS support for 1.2M floppies).
BIOS:  The IBM BIOS (all three revisions) on the IBM 5150 motherboard does not support 1.2M drives/diskettes.
Hardware:  The floppy controller (photo) that IBM supplied in the IBM 5150 does not support 1.2M drives.


To gain 1.2M operation, one possible solution is here.  Another possible solution is here.



3.5" 720K diskette drives

DOS:  DOS 3.2 or later  (3.2 introduced DOS support for 720K diskettes).
BIOS:  The IBM BIOS (all three revisions) on the IBM 5150 motherboard has partial support 720K drives/diskettes.
See note 1 below.
Hardware:  The floppy controller (photo) that IBM supplied in the IBM 5150 supports 720K drives.


Note 1 You can read from and write to 720K diskettes, but not format.
The ability to format can be gained by the use of DRIVER.SYS - see here.



3.5" 1.44M diskette drives

DOS:  DOS 3.3 or later  (3.3 introduced DOS support for 1.44M diskettes).
BIOS:  The IBM BIOS (all three revisions) on the IBM 5150 motherboard does not support 1.44M drives/diskettes.
Hardware:  The floppy controller (photo) that IBM supplied in the IBM 5150 does not support 1.44M drives.


720K diskette in 1.44M drive

If a 1.44M drive is connected to the IBM supplied controller, it will be discovered that 720K diskettes can be used.
You can read from and write to 720K diskettes, but not format.
The ability to format can be gained by the use of DRIVER.SYS - see here.

Note that the 1.44M drive can be attached to either the controller's internal connector or external connector.  For external connection, see here.


1.44M diskette in 1.44M drive

One possible solution is here.
Another possible solution is here.
Another possible solution is here.