Some RS232 hints

Some RS232 hints From: graeme@ccu1.aukuni.ac.nz, sactoh0.SAC.CA.US!jak


Q: How do you connect a terminal to the RS232 tty ports when not using
the standard IBM cable & terminal transposer?
A: 1- Connect pins 2->3, 3->2, 7->7 on the DB25's
2- On the computer side, most of the time cross 6->20 (DSR, DTR).
Some equipment may require connecting 6, 8, and 20 (DSR, DCD, DTR).

Also, pin 1 (FG) should be a bare metal wire and the cable should be
shielded with a connection all the way through. Most people don't run
pin 1 because pins 1 & 7 (SG) are jumpered on many equipment.

When booting from diskettes, the port speed is always 9600 baud. If you
use SMIT to set a higher speed (38400 is nice) for normal use, remember
to reset your terminal before booting.

Q: How do you connect a printer to the RS232 tty ports
A: 1- Connect pins 2->3, 3->2, 7->7 on the DB25's
2- On the computer side, loop pins 4->5 (CTS & RTS)



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