one of my more interesting jobs (for some values of interesting)was programming an ibm 7171 protocol convertor that took the 3270 codes that our ibm 4381 super

one of my more interesting jobs (for some values of interesting)was programming an ibm 7171 protocol convertor that took the 3270 codes that our ibm 4381 super-minis spat out and converted them to ascii sequences that our serial terminals could understand, and the reverse for things like cursor keys coming from the ascii terminals. this involved writing tables using a limited regex-like language, a bit like termcap/terminfo on unix. you could actually load a revised table (these things were difficult to debug) while the 7171 was running, and even sometimes get away with it, without crashing all user sessions. like all ibm kit of that era (mid 80s) the thing was beautifully built and documented