At 10:13 Uhr -0700 2.6.2002, Randy Beaudreault wrote:
>I just read this on the OS X Unix list and thought this would be of
>interest here with all the 68k floppies having no access and this
>being a driver for the SWIM3 floppy chip.  Is the SWIM3 on 68k Macs
>or just IWM?

We have IWM in m68k Macintoshes (vanilla Macintosh II), SWIM (probably all
DMA-less 680[23]0 Macintoshes and the Quadra 700), SWIM II (later 68040
models), IOP based floppy controllers (IIfx, Quadra 9x0) and a DMA based
controller (840AV).

Code for the DMA-based SWIM III has been available for years in the MkLinux
kernel sources, afaik even with an acceptable license. Most likely, the
Darwin code came from there. Unfortunately, driving the MFM mode requires a
lot of manual work in the early (PIO) SWIM controllers that are only
loosely related to the SWIM III. That work is hard to do without even a
description of the chip registers.

	hauke


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