... as in Kildall's PL/M language ...
By 'eck, not come across that for a while. Remember programming in that on an Intel MDS (Micro Development System) <cough> years ago. We had a "posh" version - as well as the inbuilt SD floppy drive, we had an expansion cabinet sat on top with two DD 8" drives. What a clatter they made with their solenoid loaded heads - and I recall it two two full width VME boards in the expansion crate to drive them.
As an aside, that was for an automated cable test set. IIRC (and without giving too much away), it was for testing multicore cables in situ (on board whatever boat was under construction so had to be hand portable) - and so had to do all signalling between the two ends via the cable under test. Did basic wiremap, then conductivity, and IR. Voltage and current programmable up to <several kV> and <several A> and durations up to <many days>. Would automatically do IR tests for each conductor to "all the rest together". Test requirements were stored on a 3 1/2" floppy (custom format !), I recall we could print the results or display them on a screen - but I don't recall whether we could save them on disk.
Thankfully I was only a junior engineer on the project. I could see the brown stuff just waiting to fall on the fan very early on - it suffered from, being polite, some poor design decisions at the start and eventually got canned.
One of those poor decisions was to build one unit to do two different requirements - the max voltage was increased to handle an in-house job, which made the switching more bulky and so we got less channels in one cabinet compared to what the customer actually wanted. The customer didn't want 3.5kV - can you imagine what the relay matrix for hundreds of cores, each switchable to A or B, looks like ? We could certainly have managed a smaller matrix (and hence more cores/chassis) for lesser requirements.
Still, interesting project - analogue and digital design, PCB layout, and coding. Ended up reworking both the conductivity and IR test modules (designed by others) when "oversights" in the original design resulted in us letting the smoke out of both.