1. RFC 0311
UCSB Computer
NETWORK WORKING GROUP                             Research Lab.
REQUEST FOR COMMENTS # 311                        Roland F. Bryan
NIC #9341                                         29 February 1972


   The MLC/360M

   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

   New Consoles

   In addition to our standard attachments, which are mostly Culler-Fried
   graphic display consoles and educational classrooms

                                                                [Page 1]
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.

       [ This RFC was put into machine readable form for entry ]
       [ into the online RFC archives by BBN Corp. under the   ]
       [ direction of Alex McKenzie.                   12/96   ]

                                                                [Page 2]
  1. RFC 0311