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