Re: How can clueless seller tell if IIgs is a ROM 3?

[Warren Ernst <wernst@gmail.com>]

On Oct 6, 8:11 am, magnusfalkirk <dean.pha...@gmail.com> wrote:
> Linard,
>
> I don't think there is an easy way to tell the difference from the
> outside. The only other option I can think of, instead of turning it
> on, would be to ask the seller to open it up and see if it has 1MB of
> memory onthe motherboard.
>
> Dean
>
> On Oct 6, 10:03 am, Linards Ticmanis <ticma...@gmx.de> wrote:
>
> > Hello to all,
>
> > is there some easy-to-discern and unambiguous outward physical
> > difference between a ROM 3 and a ROM 0/1 Apple IIgs
>
> > a) that can be picked out in blurry photos, or
>
> > b) that I can ask an eBay seller to check?
>
> > I'm referring to something that does not require powering on (or even
> > opening up) the unit.
>
> > Is there any such mark, for example a different arrangement of I/O ports
> > on the back side of the machine? I've never had access to a real IIgs
> > before.
>
> > --
> > Linards Ticmanis

I agree that outward appearances make the ID pretty tough. I guess a
serial number at the bottom of the case might work, but A: I'm
guessing a lot of ROM3 boards were swapped into ROM1 cases, and B: I
certainly don't know what the serial-number cutoff for the ROM1 to
ROM3 switch. Maybe someone else does.

So really, if you want to be sure, a quick look into the case is
really necessary, and then it gets pretty simple:

If the battery is purple and soldered directly to the motherboard (you
can see it under the power supply) then it is a ROM1. ROM3's have
their batteries within a black plastic bracket, and the battery is
easily removable and replaceable.

There are lots of other things that are "obvious" that someone
unfamiliar with Apple IIs probably couldn't be counted on to
recognize. The ROM3s have more ram on the motherboard - 8 ram chips
grouped together right in the middle, while the ROM1 only has 4 right
in the middle, and those 4 are labeled FAST RAM. The ROM3 only has a
16-pin DIP joystick connector on the motherboard, while the ROM1 also
has either connectors or solder points for a //e-style keyboard,
numeric keypad, and power supply connector.

The ROM3 has 2 rectangular big chips next to the 65016 CPU chip, while
the ROM1 only has 1 big rectangular  chip.

Hope this helps,
Warr