While sitting in the Lovelace class room in the Computer History Museum I saw a large picture of the ‘Radiation Printer’ that was installed at Livermore. I recognized Mona Millings operating the machine. The machine produced fan folded ‘paper’ at the rate of about 7 pages per second. The prominently displayed paper roles each weighed 600 pounds. Printer operation included mounting magnetic tapes, which would be printed in about two minutes. (The linear speed of the tape was near that of the paper.) There were two tape drives which alternated providing data to print. Mona could keep up with the combined tasks of mounting tapes, changing paper, and separating printouts according to visible marks produced by the printer. When Mona was absent, not one, not two, but three other operators were required to stand in for her. It was for a few years the critical point of the computation facility.

The mag tape was 7-track including parity; the character set was limited to 64. A tape block always began the next page.

I learned later that the paper moving technology had been adapted from the design of a small commercial printing press. I recall that the internal digital logic was ‘magnetic logic’. I do not and did not know what that meant but I think that there were magnetic cores within for purposes other than storage. It was built by a Florida company by the name of “ Radiation Incorporated”. It took a fair amount of maintenance, but it held up under 10 to 15 hours per day of operation.