Re: apple II roms and eproms

[David Wilson <david@uow.edu.au>]

"Igor" <ikanja@despam....com> writes:
>Reading past messages I've understood that AppleII+ roms are not pin
>compatible with eprom chips. Is that true also for Apple IIe/IIc/IIgs
>roms?
>If not, what kind of eproms should I use to back up or substitute them?

				ROM	EPROM	pins
Apple II & II+
Integer/Applesoft/Monitor	2316B	none	24
Rev 0-6 Text ROM		2513	none	24
Rev 7 and RFI Text ROM		2316B	2716	24

Apple IIe and IIc
Keyboard ROM			2316B	2716	24
NTSC Video ROM			2332B	2732	24
Canadian Video ROM		2364A	68764	24
PAL Video ROM			2364B	2764	28
IIe CD & EF			2364B	2764	28
IIe CF				23128	27128	28
IIc original			23128	27128	28
IIc 3.5/memx/IIc+		23256	27256	28

Apple IIgs
ROM00/01/03 1 megabit		???	none	28

Note that the 2316B has 3 chip enable inputs whose
active level can be specified by the purchaser. Apple
chose levels that were not compatible with the 2716
/CE /OE and Vpp inputs for the Apple II. With the Rev 7
Text ROM they used a 2716 compatible set of chip enables.

The IIgs uses a 28 pin 1 MegaBit (128KB) ROM but the
equivalent EPROM has 32 pins...
-- 
David Wilson  School of IT & CS, Uni of Wollongong, Australia