Re: 264/TED/Plus4 Story

From: Gerrit Heitsch <>
Date: Thu, 27 Oct 2011 22:08:49 +0200
Message-ID: <>
On 10/27/2011 09:52 PM, crock wrote:
>>> All the cpu's are 7501's and plastic. The earliest one is week 51, 1983.
>> Are they all R1 or are there other revisions? I only have a single
>> 7501 which is an R1 from 2684. All the other CPUs are 8501R1.
> The 7501's from late '83 have no revision number, the early '84 ones all
> say R1. The latest ones I have are from week 14, 1990 which are also R1!

That's interesting since I have a 8501R4 from 4986. How come they went 
back to R1 in 1990? Those from 1990 are 8501 and no longer 7501, right?

> I don't know how much has to change to get a new revision number but
> those ones from 1990 run *MUCH* cooler than all the others, which get
> hot to the point of burning your fingers. I always heatsink them now.

Same here... TED, PLA and CPU get a heatsink and I replace the ROMs with 
properly programmed 27C128. Saves some power and therefore produces less 
heat inside the case. So far I haven't lost a CPU. Maybe the ones that 
are still working are not as fragile as the ones that died already. :)

>> What does surprise me is that the 8501 was still made in 1990, looks
>> like MOS kept making spares even though the 264 line was dead.
> IMHO, the cpu expires more frequently than the TED.

Back then everyone agreed that TED was more fragile, especially the 
8360R1 version. Seems everyone was wrong after all.

> I found a source of
> 8501's in China last year and got 12 working ones.

Interesting... All genuine MOS/CSG, no fakes?

> I then bought several
> 'defective' +4's and 16's of ebay and got all of them working. ~70% had
> dead cpu's.

And all of the dead CPUs were made in 1984?


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Received on 2011-10-27 21:00:03

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