by Palmer Hanson

A calendar printing program was one of the challenges accepted for HP and TI programmers during the so-called friendly competition sponsored by by Richard Vanderburgh of 52 Notes and Richard Nelson of the PPC Calculator Journal. For the TI-59 the effort ran from May 1978 through May 1981 and involved many of the most innovative programmers including the work of seven of the "TI-59 People" listed elsewhere in this site. The first calendar printing programs for the TI-59/PC-100 by Jaren Weinberger and Lou Cargile were published in the May 1978 issue of 52 Notes (v3n5). The programs required thirty-four minutes to print out a year. Richard Vanderburgh included a program of his own in the same issue which was based on the Weinberger and Cargile programs but which reduced the print time for a year to twenty-six minutes. The next issue of 52 Notes (v3n6, June 1978) published a revised program by Lou Cargile and Fred Fitzgerald which reduced the print time for a year to ten minutes, a program by Bill Skillman with a print time of seven and one-half minutes, a program by Panos Galidas using code methods devised by Maurice Swinnen which printed a year in five and one-half minutes, and a program by Richard Vanderburgh using the methods devised by Maurice, Bill and Panos which printed a year in five minutes. The July 1978 issue of 52 Notes (v3n7) published even faster programs by Lou Cargile and Panos Galidas that used HIR commands to increase the time to print a year to just under three minutes. The September 1978 issue of 52 Notes published a program by Panos Galidas which would print a year in just two minutes thirty-nine seconds. The program included extensive use of HIR commands and data packing using all thirteen digits of the data registers. At that time the best times for the HP product line were of the order of six minutes. Both the TI and HP programmers seem to have decided that they had done about all they could do and there was no further activity on calendar printing for almost two years.

Soon after the advent of the HP-41 in early 1980, Roger Hill wrote a program for that machine which would print a year in two minutes nineteen seconds. The July/August 1980 issue of the PPC Calculator Journal (v7n5) published Roger's program and claimed the lead for the HP product line for the first time. Their lead was short-lived, for Palmer Hanson had applied Martin Neef's fast mode technique to Panosa Galidas' program and the August 1980 issue of TI PPC Notes (v5n7) published his program which would print a year in only one minute thirty-two seconds. The December 1980 issue of TI PPC Notes (v5n9-10) reported that Palmer had reduced the printout time for the TI-59 to one minute twenty-six seconds by incorporating an idea by Richard Snow to separate print commands so that calculations would continue while printing was in progress. Late in 1980 Roger Hill responded with an HP-41 program which would print a year in just one minute fourteen seconds. That time was just one second more that the thoretical minimum printing time. Finally, in mid-1981 Patrick Acosta incorporated fast mode entry using the h12 technique into Palmer's program which made room for other improvements which reduced the print time for the TI-59 to one minute twenty-three seconds. That program was not published until March 1984 in the v9n2 issue of TI PPC Notes.