found one dual stamped [INTEL 8080A & 1820-1701].
"House numbered" parts
always seemed like odd thing to do--duplicated a lot of effort---did
they think they were hiding propriatiary information by obscuring the
actual #'s on chips, transistors, etc?
That and also it made their inventory easier as 1820-xxxx was their number
and they didn't have to cross it to a drawing with their number.
Allison