VA(4)                                                                    VA(4)



NAME
       va - Benson-Varian interface

SYNOPSIS
       controller va0 at uba0 csr 0164000 vector vaintr
       disk vz0 at va0 drive 0

DESCRIPTION
       (NOTE: the configuration description, while counter-intuitive, is actu‐‐
       ally as shown above.)

       The Benson-Varian  printer/plotter  in  normally  used  with  the  line
       printer  system.   This  description  is designed for those who wish to
       drive the Benson-Varian directly.

       In print mode, the Benson-Varian uses a modified ASCII  character  set.
       Most  control  characters print various non-ASCII graphics such as dag‐
       gers, sigmas, copyright symbols, etc.  Only LF and FF are used as  for‐
       mat effectors.  LF acts as a newline, advancing to the beginning of the
       next line, and FF advances to the top of the next page.

       In plot mode, the Benson-Varian prints one raster line at a  time.   An
       entire  raster  line  of bits (2112 bits = 264 bytes) is sent, and then
       the Benson-Varian advances to the next raster line.

       Note: The Benson-Varian must be sent an even number of  bytes.   If  an
       odd  number  is sent, the last byte will be lost.  Nulls can be used in
       print mode to pad to an even number of bytes.

       To use the Benson-Varian yourself, you must  realize  that  you  cannot
       open  the device, _/_d_e_v_/_v_a_0 if there is a daemon active.  You can see if
       there is an active daemon by doing a _l_p_q(1) and seeing if there are any
       files being printed.  Printing should be turned off using _l_p_c(8).

       To  set  the Benson-Varian into plot mode include the file <_s_y_s_/_v_c_m_d_._h>
       and use the following _i_o_c_t_l(2) call

              ioctl(fileno(va), VSETSTATE, plotmd);

       where _p_l_o_t_m_d is defined to be

              int plotmd[] = { VPLOT, 0, 0 };

       and _v_a is the result of a call to _f_o_p_e_n  on  stdio.   When  you  finish
       using  the  Benson-Varian in plot mode you should advance to a new page
       by sending it a FF after putting it back into print mode, i.e. by

            int prtmd[] = { VPRINT, 0, 0 };
            ...
            fflush(va);
            ioctl(fileno(va), VSETSTATE, prtmd);
            write(fileno(va), "\f\0", 2);

FILES
       /dev/va0

SEE ALSO
       vfont(5), lpr(1), lpd(8), vp(4)

DIAGNOSTICS
       The following error numbers are significant at the time the  device  is
       opened.

       [ENXIO]   The device is already in use.

       [EIO]     The device is offline.

       The following message may be printed on the console.

       va%d: npr timeout.  The device was not able to get data from the UNIBUS
       within the timeout period, most likely because some  other  device  was
       hogging the bus.  (But see BUGS below).

BUGS
       The  1’s (one’s) and l’s (lower-case el’s) in the Benson-Varian’s stan‐
       dard character set look very similar; caution is advised.

       The interface hardware is rumored to have problems which can play havoc
       with  the  UNIBUS.   We  have intermittent minor problems on the UNIBUS
       where our _v_a lives, but haven’t ever been able to pin  them  down  com‐
       pletely.



4th Berkeley Distribution        May 14, 1986                            VA(4)