Re: DOS 3.2 controller ROM

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

In article <CuD5wn.3tB@cs.umu.se>, Christer Ericson
<christer@cs.umu.se> wrote: 
> In <31nseg$1o4@pith.uoregon.edu> nparker@cie-2.uoregon.edu (Neil
> Parker) writes: 
> 
> >>1) Both the boot and state machine ROMs are different between the
> >>   3.2 and 3.3 controllers, though they're all the same ROM (a
> >>   74S471-type) part -- a fuse-link programmable chip.
> >
> >And yes, it is just a simple ROM swap...all you need to change are
> >the two ROM chips.
> 
> Is there someone here who has the equipment to make a dump of the
> contents of the state machine ROM, for both DOS 3.2 and 3.3? I would
> be _very_ interested in these. Yes, I know that Beneath Apple ProDOS
> has an appendix on the DOS 3.3 state machine ROM, but since table D5
> and figure D2 don't match, I'd rather have a dump to dig into myself...

Better solution: get "Understanding the Apple IIe" by Jim Sather,
published by Quality Software (Resource Central has all the remaining
stocks).  It has a detailed description of the operation of the disk
controller card, including circuit diagram, description and listing of
the logic state sequencer ROM (13 sector and 16 sector versions).

The listing is much easier to follow than the silly shading-coded
chart in BAP.
-- 
David Empson
dempson@actrix.gen.nz
Snail mail: P.O. Box 27-103, Wellington, New Zealand