Re: Blame the Cable
Two types! Hoe naive!
There were dozens of different pin layouts for RS-232 and it's it's compatible variants. Everyone did it their own way.
Firstly, there is the type device (DTE or DCE), then the yype of connector (DB-25, DB-15, latterly RJ-45 [8P8C] and some horrendous proprietary connectors [IBM, I'm looking at you]) , then the gender, then the flow-control variants, and the redness pins (DCD, DTR etc.).
And finally, if you were unlucky, there was synchronous and asynchronous (yes, RS-232 could be clocked!). And remember, there was no Internet to look these things up!
I was very used to breaking out a line indicator (a straight through interposer with bi-coloured LEDs on nine of the common lines) or a protocol analyzer to try to get devices from two different manufacturers working together. Sometimes you could guess from the documents of each system, sometimes it was necessary to just work it through.
Rather than buy the wireable interposers, I often resorted to two DB-25 connectors held together with long bolts with multiple nuts, and soldered wires running between the pins at each end. If I was lucky, I would find some heat-shrink to wrap them in, but often they were left open, I know Tandy and companies like Inmac did quite a trade in specific cables and interposers, and would sell kits to make up your own interposers at quite a premium. RS had connectors with push in pins to do something similar.
Happy days spent grovelling around behind the back of mini-computers. With the state of my joints, muscles (and late-middle age spread!), not something I would want to be doing much now.