IBM 1620 Simulation

Chuck Guzis cclist at
Thu Aug 26 21:53:57 CDT 2021

On 8/26/21 7:16 PM, jim stephens via cctalk wrote:
/ printer / cpu setup wasn't too hard to run.
> Run assembler if you want to study for a while.

Back in the day, you knew that you'd arrived when you could mentally
assemble a one-liner console program and type it in without resorting to
pencil and paper...

But yes, IIRC, there's a one-card/one-line boot loader for Monitor--you
can't boot directly from disk.  The loader specifies where Monitor is
and where input will be coming from (card, paper tape, console).

One thing that throws a lot of folks is how primitive the disk monitor
system is--there are no files, per se--just permanently-assigned disk
locations for various things.   Back in the day, I used to store some of
my work on the last couple of cylinders in the work cylinders.  Very
often, in spite of the system being used by others most of the time I
could recover my data.

Like I said, it's not the same under simulation.  But that can be said
for just about any old machine.   I doubt that running an LGP-30
simulation is anything like running on a real LGP-30.


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