PC11 High-Speed Paper-Tape Reader/Punch Control
There are two versions, both of which plug into an SPC slot. The first is a dual card, the M781, which is used with an M105 Address Selector and an M782 Interrupt Control (both tall singles). The second is a single quad board, the M7810.
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. The cables are different between the two versions of the PC11; the first has H807 connectors on the side of the card into which small PCBs with plated contact fingers plug; the second version uses a pair of female-shell/male-pin Berg connectors.
The two versions are programming-compatible. The device has four control registers, which can be configured to any four sequential word locations in the I/O page; it is normally configured to addresses 777550-777556:
|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)
|ERR||Unused||BUSY||Unused||DONE||INT ENB||Unused||RDR ENB|
Reader Buffer Register (PRB)
Punch Status Register (PPS)
Punch Buffer Register (PPB)
The PPB does not respond to 'read' cycles on the UNIBUS.