On Sat, 14 Jan 2017, Chuck Guzis wrote:
Given all of that, the 1620 did perform lots of useful
work. Later
versions of the machine after the CADET added functionality, but AFAIK,
never addressed the problem of the inability to read the P-counter from
a program.
half a century ago, there was a 1401 emulator that ran on the 1620, and
PDQ FORTRAN.