🚀 go-pugleaf

Standard NULL-MODEM

The following table gives the connections for the standard NULL-MODEM as
sold by most computer supply companies.

Use two DB25 connectors and a short piece of cable or some wire. Most are
sold with female on both ends but you can customize it for your needs.

		CONN-A	CONN-B
		--------------

		1	1
		2	3
		3	2
		4,5	8
		6,22	20
		7	7
		8	4,5
		20	6,22
		22	4,5

This will work with most modems without modification. I use a Hayes 1200
and this. I have also used an ATT made by Penril that neesd pin 20 (DTR)
at the modem end tied to 6 (DSR) of the same end. Others I know who use
various modems from acoustic couplers to direct connect types use it one
of the two ways.

Gene Sampieri
ATT-Bell Labs
...vax135!ees