torek@horse.ee.lbl.gov (Chris Torek) (01/30/91)
The HP LaserJet II has a front panel. The PostScript interpreter
can write to the front panel, but the method is secret. (Almost
everything interesting is secret, e.g., the secret way to switch
between hardware and software flow control---just add or subtract
4 to/from the last parameter to setscc{batch,interactive}---but
that is just HP not documenting things.)
Anyway, under the executive, to display `foo' in the front panel,
type (note, PS> is the printer's prompt):
PS>serverdict begin
PS>$frontpaneldict begin
PS>switchexec 0 get 29 get 13 get begin
PS>/fpjobstate (foo) def
PS>end end end
In batch mode, the command sequence
serverdict begin $frontpaneldict begin
switchexec 0 get 29 get 13 get begin
(hello) setdisplay 2000 pause
end end end
should put `hello' on the display for 2 seconds. (It then reverts to
whatever is in fpjobstate, I think.)
Note: use great caution here, as you have full control over the front
panel buttons. You can make these execute arbitrary PostScript code.
How do you find out more?
Use a recursive dictionary displayer to march through `serverdict'.
All sorts of goodies spill out. Many of the important dictionaries
(such as the one containing fpjobstate and setdisplay) have no name
and must be obtained with `get' sequences like the above. This is
annoying, but there is not much you can do about it.
--
In-Real-Life: Chris Torek, Lawrence Berkeley Lab EE div (+1 415 xxx xxxx)
Berkeley, CA Domain: torek@ee.lbl.gov