Integrated Woz Machine

The Integrated Woz Machine (or IWM for short) is a single-chip version of the floppy disk controller for the Apple II.

[1][2] Wozniak successfully came up with a working floppy drive with a greatly reduced number of electronic components.

[1] The floppy drive controller board, the "Disk II interface,"[2] was built with 8 chips, one of which is the PROM, containing tables for the encoder and decoder, the state machine, and some code.

To make it easier to place the controller on the main board, Wendell Sander integrated all these components into one single chip—the IWM.

This new version added the capability of reading and writing FM- and MFM-formatted (PC-formatted) floppy disks.