Return to lp CVS log

Up to [MW Coherent from dump] / coherent / f / usr / man / KERNEL

Annotation of coherent/f/usr/man/KERNEL/lp, revision 1.1.1.1

1.1       root        1: llpp -- Device Driver
                      2: 
                      3: 
                      4: Files  /ddeevv/llpp*  access  the  line-printer's  device  drivers  for  IBM  AT
                      5: COHERENT.  The drivers are assigned major device number 3.
                      6: 
                      7: The COHERENT system supports three  printers, in both cooked and raw modes.
                      8: The following gives the device name, minor device, and I/O port:
                      9: 
                     10: /ddeevv/llpptt11 0  0x3BC  (/etc/mknod /dev/lpt1  c 3   0)
                     11: /ddeevv/llpptt22 1  0x378  (/etc/mknod /dev/lpt2  c 3   1)
                     12: /ddeevv/llpptt33 2  0x278  (/etc/mknod /dev/lpt3  c 3   2)
                     13: /ddeevv/rrllpptt11128  0x3BC  (/etc/mknod /dev/rlpt1 c 3 128)
                     14: /ddeevv/rrllpptt22129  0x378  (/etc/mknod /dev/rlpt2 c 3 129)
                     15: /ddeevv/rrllpptt33130  0x278  (/etc/mknod /dev/rlpt3 c 3 130)
                     16: 
                     17: ``Cooked'' processing  processes the special characters  BS (backspace), HT
                     18: (horizontal tab), LF (line feed),  FF (form feed), and CR (carriage return)
                     19: appropriately; raw processing simply passes them on to the printer.
                     20: 
                     21: _K_e_r_n_e_l _V_a_r_i_a_b_l_e_s
                     22: Please  note  that the  COHERENT  286 kernel  references  variables with  a
                     23: trailing  underscore character;  for  example, aattppaarrmm_.   The COHERENT  386
                     24: kernel, however, does _n_o_t use a trailing underscore; for example, aattppaarrmm.
                     25: 
                     26: The following descriptions apply to both COHERENT 286 and COHERENT 386, but
                     27: the notation will be in the COHERENT-386 form.
                     28: 
                     29: _D_i_s_c_i_p_l_i_n_e
                     30: The driver  uses a hybrid busy-wait/timeout  discipline to support printers
                     31: efficiently that have varying buffer sizes in a multi-tasking environment.
                     32: 
                     33: The kernel variable LLPPWWAAIITT sets the  time for which the processor waits for
                     34: the printer  to accept  the next  character.  If the  printer is  not ready
                     35: within the LLPPWWAAIITT period,  the processor then resumes normal processing for
                     36: the number  of ticks set  by by the  kernel variable LLPPTTIIMMEE.  Thus, setting
                     37: LLPPWWAAIITT to  an extremely  number (e.g.,  1,000) and LLPPTTIIMMEE  to a  very small
                     38: number  (e.g., one)  results in  a fast  printer, but  leaves very  few CPU
                     39: cycles available for anything  else.  Conversely, setting LLPPWWAAIITT to a small
                     40: number  (e.g., 50)  and LLPPTTIIMMEE  to a  large number  (e.g., five)  result in
                     41: efficient  multi-tasking but  also  results in  a slow  printer unless  the
                     42: printer  itself contains  a buffer  (as is  normal with  all but  the least
                     43: expensive printers).  By default, LLPPWWAAIITT is set to 400 and LLPPTTIIMMEE to four.
                     44: 
                     45: We recommend that you set LLPPWWAAIITT to no less than 50 and no more than 1,000,
                     46: and LLPPTTIIMMEE to no less than  one.  To change the values of LLPPWWAAIITT to 500 and
                     47: LLPPTTIIMMEE to one, use the following command:
                     48: 
                     49:     /conf/patch -k /coherent LPWAIT=500 LPTIME=1
                     50: 
                     51: The kernel  variable LLPPTTEESSTT determines whether the  device driver checks to
                     52: see  if the  printer is  in  an ``on-line''  condition before  it uses  the
                     53: device.  If your printer does not  support this signal, you must set LLPPTTEESSTT
                     54: to zero.
                     55: 
                     56: _F_i_l_e_s
                     57: /ddeevv/llpp* -- ``Cooked'' printer interfaces
                     58: /ddeevv/rrllpp* -- Raw printer interfaces
                     59: 
                     60: _S_e_e _A_l_s_o
                     61: aasscciiii, ddbb, ddeevviiccee ddrriivveerrss, eeppssoonn, llpprr

This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.