Roll of teleprinter paper containing instructions to the magnetic tape operator, 20th March 1971.

When unrolled, this roll of 8.5" paper extends for about 20 feet. It represents instructions printed on a teleprinter in the mag tape room adjacent to the main Atlas computer room at Manchester, during the period 10:05hrs to 19:46hrs on 20th March 1971. Most instructions told the operator to mount particular reels of tape on particular decks, etc. By looking at the names of tapes, it may be deduced that the Ferranti Computing Service was running jobs for much of the period. There are mag tapes mentioned which are labelled NWGB (presumably North West Gas Board) and Mawdsley, who were manufacturing and wholesale chemists. (The Mawdsley jobs were some of the earliest commercial data-processing jobs to be run regularly on Atlas). The teleprinter print-out also contains some fault-monitoring information. For example there is a message at 14:19:49 saying “Illegal function in Supervisor".