A friend and I are trying to repair an old HP counter (HP 5345A).
One of its faults is a failed HP 1820-0610 , which has the commercial
equivalent MC8309P. Does anyone on this list know a reasonably priced
source of MC8309P?.

Alternatively, I understand that this is a TTL part of some description,
and I was wondering if it could be functionally replaced with one
or more modern faster parts. However I do not have a data sheet,
and cannot find one on the web. Does anyone on the list know where
I can find a datasheet?

Many thanks

Stewart G3YSX