Re: II+ vs IIe Char Gen PROMs and Shift-key mods-- LC $F8 PROM mod

[david@uow.edu.au (David Wilson)]

Rubywand <rubywand@swbell.net> writes:
>Definitely. The PROMs to use are the ones which match the TI 2516 / Intel 2716
>pinouts. For some weird reason, TI's 2716 uses a different pinout.

TI based its 2716 on the 2708 (multiple power supply voltages) unlike Intel
who went to a single 5v supply.

TI then came out with a 2532 (5v only) with a different pinout to the 2732
(again 5v only). Fortunately things settled down after that and the 27xxx
series became the standard.

>> If you have a Language Card, it already has two solder points to convert it
>> to 2716 polarity. A third point marked F8 should be left open unless you want
>> the motherboard F8 PROM used when the motherboard BASIC is selected.

>     Neat to know! Is this stuff documented somewhere on-line?

Not that I know of. I got this from Jim Sather's book. I made one error in
my paragraph above. I was describing the Firmware card not the RAM card. The
RAM card has two jumpers to change to allow a 2716 to be used but no F8 jumper.

Of course most people have non Apple 16K RAM cards and will not have a ROM
socket on them. They will have to try one of the previously described methods
for replacing the motherboard ROM.

If on the other hand you have a clone motherboard, it will be likely to have
2716 EPROMs instead of 2316B ROMs (assuming they went to the trouble of
having their own monitor).
--
David Wilson  School of IT & CS, Uni of Wollongong, Australia  david@uow.edu.au