3 Nov
2024
3 Nov
'24
1:45 p.m.
On 11/3/24 12:56, paul.kimpel--- via cctalk wrote:
On card-oriented CADETs, there were a few alternatives to the nuisance
of having to multipunch a record or group mark on an 026. I seem to
recall that a period read numerically translated to 8-2-1 and worked
just as well.
Among other shortcomings of the 1620, there was no way to test for
numeric blank (8-4). You just had to know that it was there. There
were several such bugaboos, with which Dijkstra had issues. Still, the
1620 was capable of doing real work--and its 1710 relative was capable
of industrial process control application.
--Chuck
CAREY SCHUG wrote:
2. remember
that record mark? if you ever executed an instruction with a record mark in
the address, you got a MAR check red light, a hard reset was required to escape.
probably
if in the op code also. And some hard stop for any invalid op code, but these may have
been in the category below.
Shouldn't these be considered good error-trapping features and not in the same league
as HCF? An RM had the 8 and 2 bits set, so it wasn't a valid decimal digit, and
couldn't be used in an address. An RM in the Q field of an immediate instruction was
okay, though.