I do note that the Bell history said they intended for very long
> product lifespans, so anything they made had to be able to withstand
> many years of service. I believe they didn't change this philosophy
> until the 1970s when rapidly changing electronics kept making
> components obsolete quickly. On the other hand, it seemed IBM
> recognized this in the 1950s. IBM's tab line remained unchanged for a
> great many years but their computers changed about every five years.
As far as Bell station apparatus goes, remember that they were provided at a rate which provided full on-site maintenance. After divestiture, the Bell companies were forbidden to offer any type of station equipment. (One of the results of this rule was problems with sponsored Time of Day service, usual in places with flat rate service. The actual time machines [Audiovon?] machines were often located in the C.O. with full telco maintenance, and many of the sponsors had no idea what to do with the machines when they had to be removed and placed on the customer premises.)
Wes Leatherock snipped-for-privacy@aol.com