On Mar 19, 6:05*pm, Graeme Wall wrote:

That's expensive, it was a pound a minute (off-peak) UK - Kenya at that
time.

In the 1980s new circuits and improved technology greatly increased
the number of calls that could be handled, and lower the cost. This
likewise applied to US long distance calls.

In the 1970s, terminal equipment was still so expensive that sometimes
it was cheaper to simply run copper between two points rather than
carrier circuits. It's hard to believe how much the cost of
electronics has plummeted since then.

The high cost of electronics was a reason that step-by-step switching
equipment remained the best choice for many years. The peak
deployment of SxS wasn't reached until 1974--that is, up to 1974 they
were still adding SxS lines despite the availability of crossbar and
ESS.