Re: Q:How do I burn my own ROM01 for a WOZ GS?

[dempson@actrix.gen.nz (David Empson)]

Greg Dunn <gregdunn@indy.net> wrote:

> Our local Goodwill center has acquired a number of IIgs boxes.  I have
> a ROM 01 (or whatever it's called around here ;-) and would like to
> have a ROM 03 (ditto) to try some tricks with the slots that are clumsy
> with the 01 machines.
> 
> Anyway...  is there a reliable method to detect the ROM revision
> WITHOUT turning the machine on?

Lots of ways, if you can look at the motherboard.  Some that come to
mind:

- Battery position and mounting (in a socket on the ROM 3, soldered to
the motherboard on a ROM 00/01).

- Number of ROM chips (two for the ROM 3, one for the ROM 00/01).  They
are 28 pin DIP, roughly in the middle of the visible part of the
motherboard, and are socketed.

- Motherboard copyright/production date (1989 for the ROM 3, 1986 for
the ROM 00/01).

- IIe power supply and keyboard connection positions are present in the
ROM 00/01, but missing in the ROM 3.

- In general, the Ensoniq DOC chip (lower right corner, 40 pin DIP) is
socketed in the ROM 00/01, but soldered directly to the motherboard in
the ROM 3.  (This may not be conclusive).

- Number of RAM chips in the "fast" bank (four for the ROM 00/01, eight
for the ROM 3).  You could also identify the chip type: 64Kx4 for the
ROM 00/01, 1Mx1 for the ROM 3 (the circuit diagram mentions the part
number HM511000, but they might use other brands).  The "slow" RAM bank
is the same for both motherboards (four 64Kx4 chips).

You could probably look at the part numbers on some of the chips (e.g.
the FPI/CYA or the ROMs), but I don't particularly want to unbury my
machines to check the details right now.


It should be possible to identify the machine type from the serial
number (on the bottom of the case), but I don't know the ranges.  I
don't think Apple were stamping the manufacture date on the serial
number label that far back (they were by the mid 90's).

-- 
David Empson
dempson@actrix.gen.nz
Snail mail: P O Box 27-103, Wellington, New Zealand