
System X circuit board from digital switching subsystem, 1980
1980
1980
1974
circa 1972
1965-1971
1965-1971
1963-1969
1985-1992
2006-2010
2006-2010
1980
1957
1989
1960
1960
1953
1976
1950
1979
2017
2017
2017
1968
circa 1956
circa 1972
circa 1956
2013
1978
1973-1975
2006-2010
circa 1972
circa 1972