Re: Apple II ROM's and Adaptor - Now available!

["Grant Stockly" <grant@stockly.com>]

> Both? There are eight possible 2316 ROMs. There are three chip selects
> each with active high/low prograrming options. The Apple ][(+) uses two
> of those eight - the Rev 7 and later 2316 chargen is 2716 pinout
> compatible while the Integer/Applesoft/OldMonitor/AutoStart chips are
> all incompatible because of the choice Apple made to use pin 18 as an
> active high enable line.
>
> The 2532 has A11 (18), /E (20) & Vpp (21) so will not disable its
> output when pin 18 is high.

The pairs, both.

http://www.zimmers.net/anonftp/pub/cbm/schematics/computers/pet/answers.txt

"Two 2316 ROMs do indeed have exactly the same lines.  Theses ROMs are
arranged in pairs in a 4K block.  The 2316 ROMs have programmable
select
lines.  One is programmed to respond in the lower 2K and the other is
programmed to respond in the upper 2K.  You can exchange the two ROMs
in a
pair and the machine will function as it did before."
...

"You can also remove both 2K ROMs in a pair and replace it with one 4K
ROM in
one of the sockets.  For instance, if you have the 2316 Basic 2 ROMs in
the
2001, you can remove both 2316s in a pair and use the equivalent 2332
ROM
from the 2001N in their place.  Also, you can program a 2532 EPROM with
the
contents of a 4K block and use it instead of the original 2K ROMs.  In
fact,
this is the preferred method for replacements as it eliminates
potential
addressing conflists from 2516 EPROMs."