[net.usoft.s] How can I use my HP 7475A Plotter for S ?

govern@houxf.UUCP (W.STEWART) (12/22/83)

I just got an HP 7475A plotter, and tried to use it with S.  ( I don't know
S; I'm just the local guru trying to set up this new hardware.)  I tried
"hpgl", and some stuff was displayed that looked like S was expecting a
handshake back from the plotter, but nothing happened.  If I typed "0" onto
the line, S dumped out some more stuff.  I was using the following hardware
configuration:



	VAX tty port ---- HP2624 terminal, port 1
			  HP2624 terminal, port 2 --------- Plotter

All the circuits are equipped for XON/XOFF, and the parities and baud rates
are compatible.

Does anybody have an HP 7475A in a configuration that works?  In case it
matters, I'm using 4.1BSD UNIX(tm), but to my knowledge the "S" package is
identical for the BSD and USG 5.0.

				Thanks;
				Bill Stewart, BTL Holmdel NJ
				ucbvax!ihnp4!ho95b!wcs
				decvax!harpo!ho95b!wcs
				{BTL...}!...!ho95b!wcs
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rab@rabbit.UUCP (Rick Becker) (12/22/83)

You were right in using the "hpgl" device driver command in S
to work with the 7475 plotter.  The problem you have is in the
interface with the computer and terminal.

S supports Hewlett-Packard's HP-GL plotters in what is called 
"eavesdrop" mode -- the plotter is connected in series between
the modem and the terminal it is working with.
The plotter is configured to "normally off" position.
Whenever S wants to do graphics, it sends characters that
activate the plotter and do the picture.  S then de-activates
the plotter.  In the deactivated state, the plotter is transparent,
and lets characters pass in either direction between modem and terminal.

To use the eavesdrop mode for the 7475, you should have HP's
Y cable, Part 17455A, to make the serial connection.
(Or you can roll your own -- look in the "Interfacing and Programming
Manual" that came with the 7475.)
-- 

    Rick Becker  rabbit!rab