On Thu, 29 Apr 2021, Clem Cole wrote: > That said before you open up the case, I make sure you are cabled > correctly.   If you are using so-called 3-wire cables, then you need to > ensure RTS/CTS [4-5] are strapped and DSR/DCD/DTR [6/8/20] are also > strapped.   The terminal will ignore any I/O unless it sees these pins > asserted.  I used to do that so often for so many terminals that I could practically do it in my sleep... Having the correct crimping tool also helped :-) -- Dave, who has yet to see a full implementation of RS-232 i.e. the secondary channel etc