Re: Which //gs to buy?

[spec@vax2.concordia.ca (Mitchell Spector)]

In article supertimer@aol.com (Supertimer) writes...

>francine@xs4all.nl (Francine Smit) wrote:
>
>>how can you determine what rom version you have?
>>do you have to open the IIgs for that?
>
>You could open the IIGS to take a look.  Look for the
>chip labelled "Ensoniq."  If it is soldered in instead
>of socketed, you have a ROM 3.

    You'd be searching a long time, I've seen several IIgs
motherboards over the past decade and not a single one has
the word "Ensoniq" anywhere. What is silk screened on the
chip is the name "ICS 1261D" and the Apple part number
'343-0051-A' (Interestingly enough, the GF1 chip on my
Gravis UltraSound Card has "ICS" on it. From what I know,
that chip is essentially an Ensoniq 5506).

    A better way to identify a ROM 3 board (assuming your
in a situtation where you can't plug it in and power it
up) is to look at the name ID. It will say "Apple IIgs"
vertically along the right side of the board, while the
ROM 00/01 board says "Apple //GS" horzonitally and near
the center. Also look for a pair of ROM chips, 8 DRAMs
(1MBx1) above it, the battery visible *without* having
to remove the powersupply and a pine-green board with
gold colored pathways. Another tip, the slots are not
numbered in large print, just very tiny alphanumeric
ID--"J1", "J2", "J3", etc.

>An easier way is to just boot the computer.  If it is a
>ROM 3, then the first text screen with "Apple IIGS"
>at the top, should say ROM 3 near the bottom center
>of the screen.

    Yep, that is the easiest way to tell revisions of
the Apple IIgs apart--turn it on and look at the boot
text screen. The original ROM 00 shows nothing except
for the words "Apple IIgs" at top, center screen. The
other two revision do this, plus add a short copyright
notice and report the ROM revision (ROM 01 or ROM 3)
in the lower half of the screen.

    Telling a ROM 00 and ROM 01 apart without powering
it up requires you look at the part number of the ROM
chip. '342-0077-A' is the ROM 00, while '342-0077-B' is
the ROM 01 (or without memorizing those, just remember
to check the copyright dates. The chip with '87 on it
is the newer one).

Mitchell Spector
spec@vax2.concordia.ca