21 Aug
2000
21 Aug
'00
10:36 p.m.
On Aug 21, 20:28, Sellam Ismail wrote:
On Mon, 21 Aug 2000, FBA wrote:
> 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).
Look at the PROMs on the controller. On a 13-sector card, the chips are
type P5 and P6; on a 16-sector, they are P5A and P6A. Occasionally, you
may find one original (no 'A') and one 'A'. I forget which is which, but
one of the PROMs contains code and the other is a state machine; it was
possible to upgrade the code for slightly better reliability without going
all the way to 16-sector.
--
Pete Peter Turnbull
Dept. of Computer Science
University of York