I stumbled over this document:
https://insinga.com/aron/antique/surveys/diebold1970.html
Some 70,000 computers were installed in the U.S. at the end of last year, according to this census taken June 30, 1969 by the Diebold Group, Inc. The graph at left projects the computer industry’s growth to 1975. The graph on page 81 [not included; N.L.] shows hardware component costs as a percentage of total systems cost. The Diebold Computer Census appears twice a year in the fortnightly ADP Newsletter published by Management Science Publishing, Inc., 430 Park Ave., New York 10022.
Aron Insinga, on who’s web page this is found, sums this up as follows:
Here is a brief Census of Computers as of June 30, 1969, although it doesn’t have any details about the machines. Only DEC, NCR, UNIVAC, and IBM had families of machines which had shipped more than 1,000 copies, although DEC reached this number by combining all of the PDP-8 models into one number. If IBM had done that with the 360 models, it would have added up to 20,255. That’s more than 1/4 of all of the commercial computers in the US! This says a lot about the dominance of IBM at that time, and the success of the 360 (and IBM’s marketing and sales forces).
(https://insinga.com/aron/antique/surveys/)
Interesting to see, how this distributed over the various models.
(I’m also somewhat surprised hat the IBM 1401-G was treated as a model of its own, but still by then the most numerously deployed computer.)
