EARLY VERSION

Circuit diagram of the early version is in the AUG81 edition of the IBM 5150 Technical Reference manual. (Link to manual here.)
This version uses minus 5 volts, whereas the later version does not.

5150_early_diskette_adapter.jpg Click on photo for larger view


LATER VERSION

Circuit diagram of the later version is in the IBM Options & Adapters manual. (Link to manual here.)

5150_later_diskette_adapter.jpg Click on photo for larger view