View source for PC11 High-Speed Paper-Tape Reader/Punch Control

The '''PC11''' is the [[UNIBUS]] [[device controller]] for the [[PC04/PC05 High-Speed Paper-Tape Reader/Punch|PC05]] [[paper tape]] high-speed reader/punch.

It uses [[programmed I/O]], with [[interrupt]]s when it is ready for/with more data.

It is a single [[DEC card form factor|quad]] card, which plugs into an [[Small Peripheral Controller|SPC]] slot. A pair of cables (one for the reader, one for the punch - to support reader-only or punch-only options) connect it to the device.

==Registers==

The device has four control [[register]]s, which can be configured to any four sequential [[word]] locations in the I/O page; it is normally configured to [[address]]es 777550-777556:

{| border=1
! Register !! Abbreviation !! Address
|-
|Paper-Tape Reader Status Register || PRS || 777550
|-
|Paper-Tape Reader Buffer Register || PRB || 777552
|-
|Paper-Tape Punch Status Register  || PPS || 777554
|-
|Paper-Tape Punch Buffer Register  || PPB || 777556
|}

In the register contents (below), bits which are read/write or unused are shown in normal font, those which are read-only are in ''italics'', and write-only in '''bold'''.

===Reader Status Register (PRS)===
{{16bit-header}}
| ''ERR'' || colspan=3 | Unused || ''BUSY'' || colspan=3 | Unused || ''DONE'' || INT ENB || colspan=5 | Unused || '''RDR ENB'''
{{16bit-bitout}}

===Reader Buffer Register (PRB)===
{{16bit-header}}
| colspan=8 | Unused || colspan=8 | ''Input Data''
{{16bit-bitout}}

===Punch Status Register (PPS)===
{{16bit-header}}
| ''ERR'' || colspan=7 | Unused || ''RDY'' || INT ENB || colspan=6 | Unused
{{16bit-bitout}}

===Punch Buffer Register (PPB)===
{{16bit-header}}
| colspan=8 | Unused || colspan=8 | '''Output Data'''
{{16bit-bitout}}

The PPB does not respond to 'read' cycles on the UNIBUS.