At 09:42 -0700 08/05/2004, jb13@gomerbud.com wrote:

>um, well yes and no. the rom is not flash upgradebull, but most mac's of the
>time had a slot for a rom simm that you could put a new simm in and the
>board would use it instead. if your old board has one you can try and put
>it in the new board, but, come to think of it, i can't remember if the 8600's
>had a rom slot. i know the 9[56]00's did, all i remember on my 8500 board is
>a cache slot.

That whole family of Macs has a ROM slot from the 7200 through the 
9600 Enhanced.   Finding something to put in it would be the trick.

I built some PCBs that plug into that slot and hold four Flash memory 
chips.   I've used them to install the latest (Kansas, $77D.34F5) ROM 
on the earlier machines, because it takes care of a Speculative 
Processing issue with G3 processors under MacOS.    If someone wants 
to hack the OF code and needs a custom ROM built, I can do that.  I 
just don't have the programming skills to hack the OF myself.   But 
if someone provides the code that needs to go on the module, I can 
put it there.

There appears to be a Write Enable pin in the ROM slot as well.  So 
in theory, one could reprogram a firmware module that has Flash 
chips, while it is in the machine.  My PCBs have provisions for 
hooking up the WE pin to the Flash chips, but as built, I just tied 
them high (they're active low).

Jeff Walther