Re: Getting an Apple IIGS ..

[Mitchell Spector <mitch2gs@hotmail.com>]

"Chris Morse" <win32mfc@gmail.com> wrote:

>Linards Ticmanis wrote:
>>
>> The only ROM upgrade that's really a ROM upgrade is from ROM 00 to ROM
>> 01. From ROM 01 to ROM 3 you can only go by a motherboard swap, since
>> much more than just the ROM is different.
>
>Thanks.  I pretty much figured that part out from reading the FAQs this
>morning.
>From what I understand, functionally, a ROM 01 and ROM 03 are pretty
>much the same except the ROM 03 systems have 1.25MB RAM stock, whereas the
>ROM 01 has 256k.  I think I read that GS/OS patches the ROM when it
>loads.
>So besides the extra RAM, there's not a big functional difference
>between 01 and 03?

    You've pointed out the most obvious differences. And yes, while granted 
the two machines are functionally the same to a casual observer (it offers
the same capabilities as the original 1986 model), there are quite a few
advantages and operational differences in the ROM 3. I described them
in great detail in a posting five years ago, click below:

http://groups.google.com/group/comp.sys.apple2/msg/17d9a8ef6d780f05?dmode=source&hl=en

    It's quite simple to spot the difference between the two motherboards
looking at a photograph, however telling a ROM 00 and 01 apart is a
bit more tricky. I noticed many ROM 00's had a large white sticker over 
the masked ROM with the part number printed, but _not_ in all cases.

    Best way to find out is to ask the seller for the part number on the ROM
chip (near center of board). It starts with 342-0077-x, but the letter suffix
is important here: "-A" is the original ROM 00, "-B" is the ROM 01.

Mitchell Spector