How do I know what ROM version my IIgs is?

cb meeks

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Jul 25, 2017, 10:23:57 AM7/25/17

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Yesterday I dug out an old IIgs that is in need of repair. Last time I powered it on (10+ years ago!) all I remember was seeing a black screen. I put it in storage and never looked back. Time to remedy that!

Anyway, before I get to work on this I was wondering how I can tell what ROM version it is? I know where the ROM chip is but the numbers don't mean anything to me. I can post pics if needed.

Thanks!

D Finnigan

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Jul 25, 2017, 10:36:28 AM7/25/17

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Look at the bottom of the case. If you see a 1989 copyright date then you
likely have a Rom 3 machine. If your case says Woz Limited on the front,
it's probably a ROM 0. Anything else is probably a ROM 01.

Statistically speaking, you probably have a ROM 01. Most common.

--
]DF$
Apple II 40th Anniversary User's Guide:
http://macgui.com/newa2guide/

Antoine Vignau

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Jul 25, 2017, 3:07:22 PM7/25/17

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if no rom version is displayed, it is a ROM 0. Otherwise, it shows ROM 01 or 3

av

Anthony Ortiz

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Jul 25, 2017, 4:03:03 PM7/25/17

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On Tuesday, July 25, 2017 at 3:07:22 PM UTC-4, Antoine Vignau wrote:
> if no rom version is displayed, it is a ROM 0. Otherwise, it shows ROM 01 or 3
>
> av

... and if you have a ROM 02 I'll buy it from you.

Polymorph

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Jul 25, 2017, 6:19:29 PM7/25/17

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The easiest ways I find for identifying a ROM 0/ROM 1 vs ROM 3 is just by looking at the motherboard:
1) ROM 0 & ROM 1 boards have the battery soldered onto the motherboard via leads, whereas the ROM 3 has a black plastic caddy that the battery clips into
2) ROM 0 & ROM 1 boards have headers or solder points for keyboard and numeric keypad, whereas these are gone on a ROM 3
3) ROM 0 & ROM 1 boards have "Apple IIgs" written horizontally on the board (looking from the front), whereas the ROM 3 has "Apple IIgs" written vertically behind the memory expansion slot

There are also the number of chips etc, but the methods above are the "easiest" to spot.

Hope that helps.

Cheers,
Mike
http://apple2.sytes.net/

Ralf Kiefer

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Jul 26, 2017, 12:37:54 PM7/26/17

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Polymorph wrote:

> There are also the number of chips etc, but the methods above are the
>"easiest" to spot.

I found these Apple numbers which are printed onto the ROM chip(s):
342-0077-A IIGS ROM-00
342-0077-B IIGS ROM-01
341-0728 IIGS ROM 3 FC-FD (prototype)
341-0729 IIGS ROM 3 FE-FF (prototype)
341-0737 IIGS ROM 3 FC-FD
341-0748 IIGS ROM 3 FE-FF
341-0749 IIGS ROM 3 FE-FF (prototype)

- Ralf

cb meeks

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Jul 27, 2017, 9:53:09 AM7/27/17

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Thanks. That means mine is a ROM 0 or 1. IIRC, the date code was 8730. Which would be the summer of 1987.

Also, the battery was soldered to the main board. Luckily, it didn't leak. I went ahead and cut it off. It still had 0.8 volts in it!

James Davis

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Jul 27, 2017, 9:04:41 PM7/27/17

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On Thursday, July 27, 2017 at 6:53:09 AM UTC-7, cb meeks wrote:
> Also, the battery was soldered to the main board. Luckily, it didn't leak. I went ahead and cut it off. It still had 0.8 volts in it!

Voltage is NOT an indication of battery life. You need to check it with a battery checker, not a voltage meter. The battery checker puts a (electrical current) load on it, also. If the current dies, the battery is (soon) dead!

cb meeks

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Jul 28, 2017, 8:33:21 AM7/28/17

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I posted this in the other thread too.

Would putting an LED on it (even with a resistor) not do the same thing? That's usually how I test batteries.

James Davis

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Jul 28, 2017, 9:35:07 PM7/28/17

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On Friday, July 28, 2017 at 5:33:21 AM UTC-7, cb meeks wrote:
> Would putting an LED on it (even with a resistor) not do the same thing? That's usually how I test batteries.

IIRC, The load should match the type of battery (its internal resistance) being tested.