Ah, I could replicate it with a bunch of time and likely emulators. There wasn't anything secret about it, just good engineering with an innovation or two. Th

Ah, I could replicate it with a bunch of time and likely emulators. There wasn't anything secret about it, just good engineering with an innovation or two. The one that was the coolest was to use coroutines to kind of invert the inner loop. In the middle of the loop was a macro call that said "Get interrupt from the OS" which simply translated as a WAIT that would fire when the particular interrupt came in. We wrapped coroutine around this to properly save and restore state. By the way, this was significantly easier than what folks have to go through with C or using that dratted asynsc/await pattern. This particular code that used the coroutine was the outbound call processing low-level stuff. I was second fiddle on that one, and the lead was a fellow who is quoted in TAOCP. We had zero single-thread errors and one multi-thread error when we stood it up. Keep in mind that this was in the days of no debuggers other than console switches.