NETWORK WORKING GROUP Research Lab.
REQUEST FOR COMMENTS # 311 Roland F. Bryan
NIC #9341 29 February 1972
NEW CONSOLE ATTACHMENTS TO THE UCSB HOST
The UCSB 360-75 is equipped with an interface unit that allows
attachment of any type of I/O device to the Multiplexor Channel and
for that device to be operated by program control as though it were a
standard IBM Control Unit. The interface, referred to as the
Multi-Line Controller/360M (MLC/360M), operates on the Multiplexor
Channel and provides 32 independently addressed I/O connections that
are grouped into 16 pairs to accommodate full- duplex I/O operation.
Each input group has a 16-bit input buffer plus related synchronizing
and control logic to make it a stand-alone control unit on the 360
channel. Similarly, each output group has a 32-bit buffer plus logic.
Attachment is achieved by connection through a data-set type connector
and I/O signal levels conform to EIA standards (RS-232 Spec.).
Both the I/O group hardware and the supporting software for the
MLC/360M are readily modified to produce any variations required for
attachment and operation of non-standard devices.
Since our primary support was for 201B data-sets at 2400 baud, we
first implemented the 16 I/O group pairs to accommodate this type of
modem in our time-shared user environment. The I/O groups have now
been variously modified to support a wide range of applications, from
300 baud acoustic coupled use to 9600 baud for multi-station classroom
In addition to our standard attachments, which are mostly Culler-Fried
graphic display consoles and educational classrooms
using such consoles, we have a Tektronix 4002A and an NIH General
Purpose Graphics Terminal (GPGT).
The Tektronix terminal can now be operated on the ARPANET and will
provide our users with upper and lower case ASCII for easier operation
with other sites. A report on this console's capability will be
The GPGT was developed by the University of IOWA for use in
Bio-Medical applications. The unit is a delay-line refreshed video
display with graphic capability and is the only dynamic type display
in use on our host computer at present. We are evaluating its
performance in our On-Line System environment. Since a user at this
terminal is also able to reach into the network, we will have some
future comments on its operation for interested persons.
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