View Single Post
  #35   Report Post  
Old September 25th 03, 06:16 PM posted to uk.telecom
Jock Mackirdy Jock Mackirdy is offline
external usenet poster
First recorded activity by TelecomsBanter: Sep 2003
Posts: 169
Default Highgate Wood experimental electronic exchange (1960s)

In article , Martin Cope wrote:

I wasn't on the course as I wasn't a software engineer - I'd moved over from
the TXE4A development team where I'd led the hardware design of the MCU
(exchange call processor) to work on the common channel signalling
protocol - No.7 was not then a finalised standard.

Of course one "feature" of TXE4(RD) was that although modular in terms of
functional units, it was virtually impossible to extend an exchange in the way
that the PO had been used to doing with Strowger. That was a hangover from
being tied to Treasury drip-feed funding. I remember going round the regions
with John Watts and Roy Appleyard, explaining the complex process needed to
extend a working exchange. The TXE4A development addressed some of the

One result was that System X RCUs were ordered as non-extensible discrete
lumps of switch.


Jock Mackirdy