[Info-vax] Programming the serial port on an Alphaserver 200

[Steven Schweda]

rtk wrote:

> [...]   When I try to read bytes sent to the
> port the program hangs.

   Probably waiting for an end-of-line.  And if you're not
sending one, then it could wait quite a while.  Of course, my
psychic powers are too weak to reveal your code, or what you're
doing.

>   If I look at the output of SHOW DEVICE/FULL
> _TT it shows TTB0 as using formatted I/O which is not what I want.

   _Who_ shows you _what_?  This appears to be nonsense, which
would be ok if it were accompanied by the evidence which might
have led to it, but on its own, you seem to be wasting time and
space.

> Also, I haven't found how to open the port for reading and writing at
> the same time.

   What, exactly, does this mean?  Please describe actual
events, not your (confused) interpretation of them.  (Or, at
least, not _only_ your (confused) interpretation of them.)

> My goal is to use the Alpha to mimic a hardware device so I can debug
> the commands that are sent to it.

   The Alpha _is_ a hardware device.  Did you mean some _other_
hardware device?

>   Ie, I want to see the data packets
> that the host computer is sending out.

   Define "data packet".  Which host computer is that?  Not the
Alpha?

>  If I can't open the
> TTB0: port for reading and writing of single bytes [...]

   For single bytes, you may need to use the SYS$QIO method.

   For useful help in general, you may need to write better.