I first used coroutines in the 1970s in Sigma 5 assembler for an application that was in an interrupt-rich environment. Once we tuned our approach, using a mac

I first used coroutines in the 1970s in Sigma 5 assembler for an application that was in an interrupt-rich environment. Once we tuned our approach, using a macro or two, the code for an process attached to an interrupt could hardly have been clearer. As a result, we were able to build a program to dial out and send text (this was in the days when the data modem and the dialing modem were separate) with no multi-thread errors and only one single-thread error. This was significantly easier than doing coroutines in C, which is allegedly close to the machine. In a later project, we discovered that bliss 36 had a built-in coroutine feature, but we didn't see any advantage to using this in building a compiler.