[Oberon] Re. Power-down restoration

W B Hacker wbh at conducive.org
Sat Jan 3 17:44:49 MET 2009

Chris Burrows wrote:

> In the 1980's, some time before UPS systems became popular, one of my
> favourite systems that I developed software on was an NCR Tower with a MC68K
> processor running NCR Unix. We had half-a dozen or so dumb terminals
> connected to it. The OS was able to detect an imminent power failure in
> sufficient time (100's of milliseconds perhaps?) to be able to save the CPU
> state, memory contents etc. etc. A small battery was sufficient to maintain
> the state until mains power was restored. As far as I recall, every user was
> then able to resume exactly where they had left off with no loss of data.

General Automation SPC-12 'Power Fail/Restart' circuit detected a 
missing half-cycle on the mains power, did all of the save-state, PC 
included, before the power-supply capacitors had lost enough charge to 

1967, and not at all new even then [1] - though magnetic-core memory (2K 
to 8K of it) played a major part in allowing a machine with a mere 600 
KHz clock to accomplish all that in 8 or 9 Milliseconds.

The irony is that GA had no 'reset' button!

My then-boss, Jack G. Frisbie, called GA execs to a meeting, demoed a 
'RESET" button he had added to his personal SPC-12, said he would 
assigen them his design rights for only US$ 10,000.

They bit - but Jack was laughing too hard to take their money for a mere 
SPST Normally Closed switch cut into the mains power lead...



[1] Not sure if AN/FSQ-7 had it, but AN/GSA-51 did.

>>>> As you know, computers won't boot if you just plug in the power
>>>> cable ;-)
>> They will if the BIOS is set to do so..
> I was once surprised to be woken up in the middle of night by the sound of
> my PC coming to life. It turned out that a phone call had been received by
> the modem and that then caused the PC to power on and boot itself up!
> --
> Chris Burrows
> Armaide: ARM Oberon Development System for Windows
> http://www.armaide.com
> --
> Oberon at lists.inf.ethz.ch mailing list for ETH Oberon and related systems
> https://lists.inf.ethz.ch/mailman/listinfo/oberon

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