Re: Who has IIc ROM that allows plat 3.5" 800K drives???

[dempson@actrix.gen.nz (David Empson)]

David Wilson <david@uow.edu.au> wrote:

> At a guess, to get a //c to run an Apple 3.5 you would need to create the
> 3.5* signal, install a Zip chip or equivalent and then rewrite the disk
> driver routines in ROM.

There is also the head select signal, which is controlled by software in
the IIgs.  It goes to another pin on the drive connector (16).

> If it were possible, why did Apple have to add extra hardware to the //c+
> (especially as it has an accelerator onboard)?

The accelerator was apparently an afterthought - they had already
designed the 3.5" drive ASIC by then.  If the accelerator had been
planned from the beginning, they could have used much simpler hardware
support for the 3.5" drive.

-- 
David Empson
dempson@actrix.gen.nz
Snail mail: P.O. Box 27-103, Wellington, New Zealand