All:
        Word to the wise -- always check the cabling. I've been wracking
 my brain this week on the serial port problems with my Altair. I wired
 the serial board cable per the manual but I never checked if it was NULL
 or not. Well, when I put a null adapter on the cable, it worked! Whoo,
 hoo. 
I don't want to say how many times I've made that sort of mistake :-)
Another word to the wise... Get one of those little in-line RS232
testers. The one I have has 7 bi-colour LEDs on it that monitor TxD, RxD,
RTS, CTS, DSR, DTR and CD. I've seen one with more LEDs too.
I'm always using mine to cheack whether an RS232 port is wired as a DTE
or DCE. Or if it drives any of the handshake lines. I find it a lot more
use than my fancier breakout boxes, comms analysers, etc.
-tony