Apple ][ disk controller state machine

From: Douglas Quebbeman <>
Date: Thu Sep 6 07:25:01 2001

> Thanks, dq. I have seen that doc, but it speaks mainly of the
> 3.5 drive, which had several enhancements not available on the
> 5.25 drive. Was the Apple ][ controller sufficiently similar to
> the IIgs and progeny that this documentation is appropriate for
> it also? I've never heard the Apple ][ controller chip referred
> to as 'IWM' -- is that my ignorance, or was the chip renamed, or
> are they (maybe slightly) different beasts?

It's my understanding that the single-chip Integrated WOZ Machine
replaced and duplicated the function of the discrete-component-based
equivalent on the Apple II family...

FWIW, the Lisa 1 and the very first non-production Macs used a strange
5.25 inch floppy known as the Twiggy Drive... I can show you photos
of Macs that had been retrofitted for the 3.5 inch drives, but those
drives are visible through huge 5.25 inch gaping holes...

So while I can't say with certainty, I doubt the original circuit
has any capability not duplicated in the IWM chips.

Received on Thu Sep 06 2001 - 07:25:01 BST

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