VAX 780 on eBay

[Guy Sotomayor]

On 1/1/22 10:40 AM, Paul Koning via cctalk wrote:
>
>> On Jan 1, 2022, at 1:12 PM, Noel Chiappa via cctalk <cctalk at classiccmp.org> wrote:
>>
>> This:
>>
>>     https://www.ebay.com/itm/275084268137
>>
>> The starting price is expensive, but probably not utterly unreasonable,
>> given that:
>>
>> - the 780 was the first VAX, and thus historically important
>>
>> - 780's are incredibly rare; this is the first one I recall seeing for sale
>>   in the classic computer era (versus several -11/70's, /40s, etc)
>>
>> - this one appears to be reasonably complete; no idea if all the key CPU
>>   boards are included, but it's things like the backplane, etc (all of which
>>   seem to be there) which would be completely impossible to find now - if any
>>   boards _are_ missing, there's at least the _hope_ that they can be located
>>   (780 boards seem to come by every so often on eBait), since people seem to
>>   keep boards, not realizing that without the other bits they are useless
> Interesting, but the argument for why it's not tested is implausible which makes me very suspicious.  I suppose there might be a few American homes that  have only 110 volt power, but I'm hard pressed to think of any I have ever seen, and that includes really old houses.

Without replacing the power controller in the 11/780, you need 208v 
3-phase to run it.  It's not impossible...nothing in the CPU actually 
*needs* 3-phase as the individual power supplies are 120v but the 
overall maximum load is greater than a 30A 120v circuit.

TTFN - Guy