A friend has an IMSAI 8080 that he still uses to burn
PROMs ... that's the
oldest one I know of.
It's nowhwere near the oldest computer still in use (since it's based on
a microprocessor), but when I need to program 1702s, I have to use my
Intellec MCS8i, since that's the only machine I have with a suitable
programmer. And that machine is older than an Imsai.
-tony