lgy@blake.acs.washington.edu (Laurence Yaffe) (10/06/89)
RC- and RS-2030s are getting shipped with only a single parallel port entry in /dev: /dev/lp. This apparently is a "canonicalizing" device designed for dumb printers which can't manage backspaces & such. It also truncates lines over 80 characters or so long, which makes it terrible for connecting to a Postscript printer like the QMS-810. Examination of the lp(7) man page (available on paper - but missing in the on-line docs) in the sys. admin ref. manual suggests that three different parallel port entries are supposed to be present: a canonicalizing interface (/dev/lp), a raw interface (/dev/rlp), and a capitalizing interface (/dev/lpc). I couldn't find the correct major & minor numbers for these devices anywhere in the documentation, but fortunately I could examine an M/2000 where one finds the following entries for the first parallel port: crw-rw-rw- 1 root 16, 64 Jul 20 18:25 /dev/lp0 crw-rw-rw- 1 root 16, 65 Jul 20 18:25 /dev/lp0c crw-rw-rw- 1 root 16, 66 Jul 20 18:25 /dev/rlp0 On the 2030, one finds: crw-rw-rw- 1 root 38, 0 Oct 2 15:36 /dev/lp This suggested that the raw interface was supposed to be at (38, 2). Creating it (using "/etc/mknod /dev/rlp c 38 2") yields a raw interface device which works fine! I presume that (38, 1) will give a capitalizing interface but I haven't bothered with it. -- Laurence G. Yaffe Internet: lgy@newton.phys.washington.edu University of Washington Bitnet: yaffe@uwaphast.bitnet