Port-vax archive

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Old Index]

Re: Serial console on second port?

Patrick Finnegan wrote:
On Monday 30 March 2009, Johnny Billquist wrote:
One nice property of MMJ is also that for a null-modem cable, you
should connect 1-6, 2-5, 3-4. So it's symmetrical. So the easy way to
see if a cable is a null-modem cable is just to inspect the
connectors. If they are turned the same way at both ends, it's a
null-modem cable, and if they are the opposite ways, it's a straight

By design, also, all MMJ cables should be null-modem. If you have to convert to DE9 or DB25 serial connectors, there's different adapters for DCE and DTE so that you always use a roll-over MMJ cable instead of a stright through one.

Unfortunately when people make their own cables and installments, they occasionally don't follow this. I've come across cables with MMJ connectors that were straight. :-(
So it's probably good to pay attention.


Johnny Billquist                  || "I'm on a bus
                                  ||  on a psychedelic trip
email: bqt%softjar.se@localhost             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol

Home | Main Index | Thread Index | Old Index