[comp.sys.dec] Hooking a VAX to Centronix Printer

ta2@cup.portal.com (Tom TA2 Allebrandi) (12/04/88)

This was discussed a few years ago in the I/O column of the Pageswapper.
(The DECUS VAX SIG newsletter.) I downloaded this from the Pageswapper
VAX Notes system.

Tom Allebrandi	Advanced Computer Consulting, Inc
(804) 977-4272	esther!ta2@edison.ge.com	(I'm not in the maps yet)
		ta2@cup.portal.com


                        INPUT/OUTPUT 349

Caption:  Centronics interface to DMF-32 -- reply to I/O # 321

Message:  We have successfully interfaced the DMF-32 to our  own
          printers,  which  are  Centronics inteface compatible.
          You may only need to  make  a  cable  and  strap  your
          printer   accordingly.    If   your  printer  has  the
          "standard" 36-pin Centronics connector (same as  Epson
          MX-80  and  others),  you  can  make  a cable as shown
          below;  otherwise you will have to locate the  signals
          on your printer connector and make a custom cable.

          DMF32
          Centronics
           J14                Signal Name
          Connector
          __               _____               _____
            8                 Strobe                         1
           26                 Data 1                         2
           20                 Data 2                         3
           22                 Data 3                         4
            1                 Data 4                         5
           24                 Data 5                         6
           23                 Data 6                         7
            5                 Data 7                         8
            6                 Data 8                         9
           18                 Busy (demand)                 11
           12                 Select (online)               13
           17                 Fault                         32
           14                 POn (conn VFY)                16
           30                 0V and Shield                 16

          Appendix C in the DMF32 User's Guide (EK-DMF32-UG-002)
          is  incorrect;   you  should  mark  J14-37  as PRINTER
          SPARE,  and  J14-8  as  PRINTER  STROBE.   Note   that
          ACKnowledge  and  PE (paper empty) are not used.  Your
          printer should be strapped to go offline  (deselected,
          local) on a fault condition;  otherwise VMS won't tell
          you anything when paper runs out.

          Additional printer strapping information:

          Busy level = low (0)
          Strobe level = high (1)
          Strobe trigger = trailing (falling) edge

          For a long cable, if  the  printer  allows,  the  data
          lines  should be sampled 300-500 nanoseconds after the
          trailing edge of the strobe pulse.

Contact:  Carl Houseman
          GENICOM Corporation
          1 General Electric Drive
          Waynesboro, VA 22980
          (703) 949-1323

Date:     November 18, 1984