|In 1970 IBM introduced a computer based solid state switching electronic PABX called
the 2750. This PABX offered the market place the first space programme controlled
switch. The 2750 was highly featured and could be modified or updated by software
The sophistication of the 2750 posed radically new areas for the BPO field maintenance staff to cover and operational experience led to the uniquely packaged variant the 27SS, being produced to test the possibilities of dual maintenance, with IBM engineers serving the Central Processor Control and BPO staff servicing the remainder of the PABX.
The 27SS was superseded in 1973 by the 3750.
Pictures take at the Havant Computer Centre - dated 1970
Last revised: May 03, 2019