DEC PDP-8/e H212 core mat repair

Rod Smallwood rodsmallwood52 at
Mon Jul 19 17:06:26 CDT 2021

Yes most core stringing was outsourced.

By hand under magnification was used.

I cant recall any references to automation.

That would br down to the supplier.

The story I heard was at least some were done by embroidery girls in 
Hong Kong

Rod Smallwood   -- Digital Equipment Corporation  1975 to 1985

On 19/07/2021 22:50, Jules Richardson via cctalk wrote:
> On 7/19/21 3:40 AM, Joshua Rice via cctalk wrote:
>> I believe much of the core manufacturing for DEC minicomputers was 
>> outsourced, but a lot of it had become much more automated by the 
>> late 60's and early 70's.
> I've got a trio of planes here, two of which are from a Lockheed 
> MAC-16, but the other one is made by Keronix out of Santa Monica for 
> an unknown machine (dated 1973, model number "P4" and p/n 816335 if 
> that means anything to anyone, approx 16"x16" with two 100-pin, 
> double-sided finger edge connectors on 0.1" spacing).
> Anyhoo, the Keronix one has a sticker on it saying it was repaired by 
> DMA, inc. in Amery, WI in 1980 - which might suggest that there were 
> third parties around working on boards, rather than them having to go 
> back to the manufacturer for repair. (I have no idea what the nature 
> of the repair was, of course; maybe it was to surrounding logic rather 
> than the mat itself).
>> It's worth noting that most computer manufacturers appreciated the 
>> fragility of core memory planes at the time, with most of them being 
>> protected with either PCB's or perspex/plastic shields on top of the 
>> core planes.
> Yes, that's how all the ones I've ever seen have been. The Keronix one 
> has an additional shield over the top of the entire PCB, on top of the 
> one protecting the cores.
> Jules

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