🚀 go-pugleaf

> If you wanted to make a DB9 to DB9 RS422 cable
> then 1 straight through, and 5&9 swapped should do it.  

I tried this first and it didn't work (probablly due to software
problems.  I then looked at an Imagewriter cable and found that it
connected:

9-pin Mac end		23-pin Imagewriter end

3 and 8			7
5			2   / these two might be swapped
9			3   \
7			(something else)

Questions:

1)	Are macs 9-pin connector's pin 1 and 3 (both called ground)
	identical?
2)	Why would pin 3 and 8 be shorted together (the Imagewriter
	does work, so it probablly isn't by accident)?  Should my
	cable short these pins?
3)	Do I need to hook mac 9-pin connector's pins 7 together?
	(Pin 7 was caled "incoming handshaking"; I guess it doesn't
	need to be hooked together, but might need to be grounded).

Any help anyone can offer will be most appreciated.  As I said before,
I suspect the problems I'm having are mostly software, but I would
like to be sure the cable is right.
-- 

Kevin Crowston				UUCP: {seismo,ut-sally}!harvard!kevin
MIT Sloan School of Management		ARPA: kevin@harvard.ARPA