using the parallel port on the alm-2

[Perry The Cynic]

> we'd like to connect a printer to the parallel port on our alm-2, but i
> can't find any documentation on which dev we should use to access that
> port....can you let us know how to enable it?

As far as naming is concerned, the ALM-2 goes under the name of "mcp".
Say "man mcp" and it'll tell you what it knows. The minor device number
for the parallel port (of the first ALM board) is 64, so our printer is

	crw-rw-rw-  1 root      40,  64 Feb  2 11:22 /dev/mcpp0

The wiring seems to use "standard" Centronics wiring; we didn't have any
problems with printers advertised to have a "centronics port" (what IBM/PC
people call a "parallel" or "printer" port).

 ** WARNING **

The man-page for mcp(4S) describes an ioctl(2) function that alledgedly
causes the device driver to issue status messages concerning the parallel
port (paper out, printer error etc.) to the console. This works, but if
you turn that function on, it will screw up the serial ports on the board.
(At least, that's what happened in our case - the serial ports would hang
anytime when *no printing* was done on the parallel port. Caused some head
scratching.) This bug may not be present in other versions/hardwares, but
be careful.

Our configuration: Sun 4/280, SunOS 3.5
  -- perry

Perry The Cynic (Peter Kiehtreiber)		     perry at arkon.key.com
** This signature under construction **		   ...!pacbell!key!perry