1 May
2012
1 May
'12
2:11 p.m.
On Tue, 1 May 2012, Tony Duell wrote:
it strikes me that one of the main moans about RS232
was that there were
straight cables and null-modem cables and this confused people. If it had
been agereed that all 'hosts' -- that is computers -- would be wired as
DTEs, and all 'slaves' -- modems, printers, etc -- would be wired as
DCEs, there would bne no problem. The problem arrose because you could
link 'hosts' (computers) directly togther with RS232.
You would have them wire printers as DCE?
My first printer was a Daisy-wheel (DTC-300 HytypeI) printing terminal.
If it were wired DCE, then how would I connect it to a modem when I used
it as a terminal instead of as a printer? GASP! I would need to make a
cable with the "transmit" pin connected to the "receive" pin at the
other
end!
I freely admit that some further standardization for serial printers would
have helped. I had that printer for months before I finally got ink onto
paper. And, in the USA, I'm aware of a documented homicide over the
frustrations of interfacing serial printers to microcomputers.
OTOH, I know somebody whose first experience with connecting a serial
printer involved him reaching into a large bin of random DB25 cables, and
selecting the first one that had the genders that he wanted. It turned
out, by chance that that one had 2 crossed with 3 and some other crosses
and ties-together between 4,5,6,8, and 20