Introduction - Control Data 1700 Maintenance Manual

INTRODUCTION
The Basic 1700 system incorporates provisions for four Input/Output devices
which operate in a non-buffered fashion. Each device has its own controller
logic. The four controllers, in turn, communicate with the computer via an
interface called the Common Synchronizer.
It is necessary to place into the 1704
Q
Register, codes which identify
completely the communications link desired. For low speed operations, the
contents of
Q
has the following format:
Where W must be all zeros, E (the equipment code) must be 0001, S (the station
code) must match the station number of the desired controller and D (the
director bit) identifies the operation as bei.ng data transfer (D
=
"0")
or
non-data transfer
(D = "1").
Station codes to be used in low-speed operations are given in table A. It
should be noted that station code 0 is restricted to non-data transfers and
applies to equipment rather than station operations. Its use will be explained
during discussion of the Common Synchronizer.
Station
0
- Common Synchronizer
Station 1 - - • Teletypewriter
Station 2 - - - Paper Tape Reader
Station
4 - Paper Tape Punch
Station 6 - - • Card Reader
Table
A
Low Speed Station Codes
vii
Rev. A