monty%tartarus@gargoyle.uchicago.edu (Monty BSD) (01/27/89)
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. i also think that we'll have to MAKEDEV, but i can't find anything on that either. has anyone used the parallel port on the alm-2 ? if so, can you let us know how to enable it (or where in the documentation we can find the info) ? --monty
perry@decwrl.dec.com (Perry The Cynic) (02/19/89)
> 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@arkon.key.com ** This signature under construction ** ...!pacbell!key!perry