--- Eric Smith <eric_at_brouhaha.com> wrote:
> Someone asked:
> > How can you tell about the original ROMs and 13 sector disk?
> > I'll bet Eric Smith knows this (as well as how to properly identify a
> > 13-sector disk controller...one clue is that it is missing the sticker
> > that has the Apple logo with a "16" inside, but that isn't a reliable
> > indicator).
>
> A 13-sector controller's PROMs are labelled P5 and P6, whereas a 16-sector
> controller has P5A and P6A.
>
> It is reasonable to upgrade a 13 sector controller to P5 with P6A. This
> retains the 13-sector boot code, but upgrades the state machine to be
> capable of reading 16-sector format. In my machine I had two controllers,
> one with P5 and P6A, the other with P5A and P6A. I would boot 13-sector
> disks from the former and 16-sector from the latter, but when 16-sector
> software was running, it could use all four drives.
Are the contents of the PROMs available anywhere for download? I happen
to have an ancient Data I/O programmer that will blow them and a *very*
limited supply of blanks (the COMBOARD-I used a pair of 256x8 PROMs for
boot ROMs) I wouldn't mind making a set of 13-sector PROMs.
-ethan
=====
Even though my old e-mail address is no longer going to
vanish, please note my new public address: erd_at_iname.com
The original webpage address is still going away. The
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See
http://ohio.voyager.net/ for details.
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Received on Tue Aug 22 2000 - 16:16:15 BST