Serial Ports, DTR and RTS/CTS

[DanKarron at UCBVAX.BERKELEY.EDU]

Dave Marks (marks at aivax.radc.af.mil) writes:

>I want to connect 3 modems (actually NIU ports, but they LOOK and ACT like
>modems) to our 4D/70GT (soon to be a 4D/340VGX).  We have the 6 serial port 
>expansion interface, but those ports don't support DTR for detecting presence
>of a connection; an attribute we require.  Ports 1-4 support DTR, but 2 and 3
>are dedicated to the Buttons & Dials Box and the SpaceBall.

I had a 70G machine, and I maintain that serial io is not right on that
class machine. I had to move to a newer machine (85) for all the serial io
problems to clear up. 

My advice is to wait until you get your 340VGX machine. The design intent
is that all the serial ports are wired the same, but that is not the
case for the 70 machines, despite what all the fe's say.
 
If you are using Ungermann-Bass NIU's, you are in for more grief. I am surprised
that the serial expansion ports don't support hardware handshake. You need
it for fast (>9600 baud) io.

Cheers!

dan.

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