PXML No. 124
APPROVAL No. NS/1210/23/H/452742
The Rolm CBXII Automatic Call Distribution is a stored program computer controlled modular
designed telephone switching system. Voice frequency connections through the switch uses
Pulse Code Modulation for speech to digital conversion, and Time Division Multiplexing for
switching the digital pulse train.
Earlier systems are known as 7000 type systems, These systems are 1 to 3 cabinet systems
and use ET5300 type telephones as agent positions, There is also an additional Adaptor
Cabinet which houses cards which allows connection of early Rolm trunk cards co the UK
PSTN. Some sites have BT Power systems 2000b fitted as standby power.
Later systems are known as 8000 type systems. These systems use ET5300A type telephones as
agent position and Rolmphones 120, 240 and 400 as feature phones. A small non-redundant
system, the VSCBX, is also available.
Some later 8000 installations use a stand alone ELTEK Power Cabinet, which provides system
voltages and standby batteries.
Conversion is possible from a 7000 type system to a "hybrid 8000" type system.
Made by Rolm Telecommunications.
Distributed initially in the UK through Plessey (GPT and now Siemens)
Systems were later distributed through IBM UK Ltd
Early systems were installed by Plessey Telecommunications and Telephone Rentals. Later
systems have been installed by IBM UK Ltd.
Extensions to existing systems should only be installed by IBM UK Limited.
Maintained originally by BT but IBM UK Ltd were approved maintainers for liberalised
system ONLY, (those are systems brought into service after lst July 1986).
Equipment Software Disc Header 7000 Type 7000 or 7000I (Release 7) 8000 Type 8000I
When the engineer signs onto the system the printed header will state the software fitted
(either release 7 or 8). Software/patches fitted are recorded on the hardware map.
Supplier
IBM UK LTD
BASING VIEW, BASINGSTOKE, HANT5. RG21 IEJ
Telephone 01256 478166
PARTS DESCRIPTION PART NO CPU 2 MN 85030 CPU 3 MN 85010 CPU 4 MN 85020 MEMORY CONTROLLER MN 84040 DTDM NETWORK CONTROLLER 1 MN 85060 DTDM NETWORK CONTROLLER 2 MN 85070 +I/D BUS SWITCH MN B5090 +REAL TIME CLOCK MN 85080 +QUAD SERIAL I/O MN B5920 FLOPPY DISK INTERFACE MN 85360 +2-CHANNEL SERIAL I/0 MN 87600 +ETA-1 MN 85660 +ETA-2 MN 85670 8 CHANNEL I/F MN B5540 16 CHANNEL CODER MN 85510 16 CHANNEL DECODER MN 85520 EXPANDER MN 85500 +CPU A MN B6200 +CPU B MN 86250 TCC CARD MN 75080A +256K MEMORY MN 86130B MEMORY CONTROLLER MN 86200 ROLMPHONB INTERFACE I MN 78011A ROLMPHONE INTERFACE II MN 79012 INTERSHELF BUS MN B5990 FLOPPY DISC DRIVE MN 88981 FLOPPY DISC I/F MN 85360B Some cards have been superseded by later revision cards. All cards with same description are compatible unless stated.
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Last revised: 26 December, 2004
FM