Apropos nothing...

hirez reminded me of antediluvian digital computingnesses. I thought of Baby's First Hack, time back way back.

I was at Hull University then; they ran an ICL 1904S with 192K words of 24-bit core. Apart from the odd weekend when they fired up GEORGE 4, the behemoth under the Brynmore Jones library ran GEORGE 3: no VM. Because of this, MOP^[1] sessions were limited to loading programs of 2K words or less. MOPCORE limit it was called. Anything larger had to be submitted as a batch job.

There's not a lot you can do in 2K words. Certainly not run the Algol68R compiler.

However, you could run a few specially privileged interactive programs of significantly greater size. So, I wrote a little command script that loaded (but didn't run) one of those programs, then copied a little program loader into the registers (1900 computers addressed their registers as the first few words of memory, so you could run code written into them). Load a program of my choice into the (already authorised and allocated) memory; execute from its normal start address and... eventually I got caught by the ops, yes, running the Algol68R compiler online. They conceded that it was a nice hack, but banned me for a week anyhow.

Ahh... Them were the days. Kids now, got no idea.

^[1] Multiple Online Programming, otherwise known as a Teletype KSR33 (or 43, if you were lucky).