Another thing to check if FAS is locking up...

[Karl Lehenbauer]

I just fought through some problems that I thought might be FAS's fault,
which turned out to be my fault.

If you configure FAS with the usual modem controls, if CTS is not present
on your connector, FAS will be polite and not output any data.  Forever.

This will behave very similarly to a misconfigured interrupt.  When you
try to output, your task will hang, and a subsequent attempt will make
the task immortal (meaning killing it won't make it go away), meaning
that the system probably won't be able to unmount one or more devices
next time you take it down (which'll be right away since you want to 
clear the problem) and try it again), meaning you'll have to suffer through
some file checks when you bring it back up.

I tend to test this stuff from a real straight, sh-based root login,
running the program out of /tmp, so if I do hang, usually only /tmp
will have to be f-checked.

In my case, sometime while jacking around with this stuff I inadvertantly
set S67 to 1 on a Telebit TB+, which basically says "Make CTS follow CD."  
I had the Telebit so wedged I thought I was going to have to open it to
look for a reset switch.  The T2500 is much cooler in this case because
you have the A/B switch and two parameter sets -- it's a bit harder to screw
up so thoroughly.
-- 
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