The Smartcom III team experience with concurrency was … the successor program, Smartcom for Windows … Several significant lessons were learned from this experience. … it took more code to write certain types … [e.g., the Zmodem file transfer code was twice as long] … loss of efficiency [due to state-driven processing] … giving up the concurrent programming model still did … the problems of non-reentrant message handlers being invoked …
Google-1
Google-2
Copyright clearance needed for quotation.