Macintosh IIx - Manufactured Feb 1991. What??

David Cook

Active Tinkerer
Jul 20, 2023
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I saw this really crisp-looking Macintosh IIx on eBay. It has the least yellowing of any case from that era that I have ever seen. (Difficult to tell in a photo with so much wood nearby)

No-yellowing-of-case.jpg


I already have plenty of IIx computers, but the serial number on this one intrigued me. It follows the IIfx encoding ('F3'). Thus, this claims to be made in 1991 ('1') on the sixth week ('06'). Yet, according to Wikipedia, the IIx was discontinued in October of 1990.

Bar-code-serial-number-1991-sixth-week.jpg


After arriving, I found a number of supporting dates to confirm this Mac IIx was really manufactured this late.

Lid-says-Jan-30-1991.jpg



Case-base-labeled-Jan-4-1991.jpg


The batteries are from December 1990.

Battery-carrier-with-Dec-1990-date.jpg


There are a number of motherboard chips with 3rd/4th quarter 1990 date codes.

Based on these dates, either:

1. Apple kept making IIx computers beyond the publicly announced discontinued date.
2. The date on Wikipedia is wrong (I couldn't find its source).

Given that the IIci and IIfx had been out for a year or more, why would anyone be buying a IIx in 1991?

The owner upgraded the RAM to 8 MB and installed a 120 MB aftermarket hard drive. The drive was full of applications, documents, and System 7.1 chock full of inits. Whoever got it sure did love it.

Any Improvements Over Earlier Boards?


The ROM is from the 49th week of 1990. Sadly, it is still the standard 32-bit dirty ROM. I guess it wasn't worth it to Apple to test the IIci/IIfx ROM in older models?

But, the battery holder appears to be factory installed. Looking at the underside of the board, there isn't any indication of hand rework to desolder fixed batteries.

Battery-holder-soldered-at-factory.jpg


Unlike the other IIx computers I've seen, this one has metal tabs in the memory slots. Sweet!

Metal-clips-on-memory-slots.jpg


Other than that, I didn't notice any other differences.


Really Clean Example

This is the nicest IIx I've ever seen. The plastic is clean and not yellowed. The metal does not have any rust or graying.

Clean-and-no-rust.jpg


Of course there was capacitor leakage. But, no traces or chips were damaged. The recapping went smoothly.

Minor-capacitor-leakage.jpg


All in all, a nice computer to have in the collection. Still a bit of a mystery why Apple would still be making these in 1991.

- David
 

This Does Not Compute

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Oct 27, 2021
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This article mentions the IIx being discontinued:


It's from March 1991, and while it doesn't cite a specific date that Apple discontinued the machine, TidBITS tended to be pretty timely with its reporting. The IIx's Wikipedia article doesn't cite a source for its discontinuation date, but does link to Apple's tech specifications page...but these have been proven to be inaccurate for various models.


My money is on TidBITS being the more accurate source here, unless someone can turn up a press release.
 
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PL212

Tinkerer
Dec 25, 2022
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Great research, and indeed a wonderfully clean example! I can easily imagine them using up the last few cases and motherboards into 1991, plus some big orders may have been awaiting fulfillment from slow-moving customers (regulated industries, governments) that would prefer tried-and-true over newer, faster and cheaper...
 

David Cook

Active Tinkerer
Jul 20, 2023
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fulfillment from slow-moving customers (regulated industries, governments

That occurred to me as well. Even if Apple announced discontinuation for consumers, I imagine they would fulfill contracts that went through a lengthy bidding/review process. This would also explain why someone would be choosing a IIx over a IIci in that time period (because they actually selected the IIx years before).
 

Nitram78

New Tinkerer
Oct 30, 2021
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Maybe they needed to make a few more to cover warranty replacements...

Just out of curiosity, what version of the power supply does it have?