Programming instructions

A complete line, or 120 columns of information, is placed in the printing
buffer. Six bits specify each character (the codes are given in Appendix 2).
The information is transferred to the printing buffer through the AC, three
characters at a time from AC bits O-5, 6-11, and 12-17. Forty load print
buffer instructions fill the 12Ocolumn line.
After the printing buffer is loaded, a print instruction is given which prints
the contents of the buffer. The action of printing does not disturb the
printing buffer. When a column of information has been printed, the print-
ing flag becomes a 1. Approximately 80 milliseconds are required to print
one line.
An eight-channel format-control tape inside the Printer moves in synchro-
nism with the paper and specifies how far the paper is to be spaced. Holes
punched in each channel of the format tape signify the next paper position.
The channel is selected by placing a three-bit code in AC bits 1517, and
giving an instruction to space paper. The spacing flag becomes a 1 when
the spacing action is complete. A recommended control tape has the
following characteristics, where the middle column indicates the number
of lines between successive holes in the channel:
Channel
Spacing Time
0
1 line 16 ms
1 2 lines <2xl6ms
2
3 lines <3x 16 ms
3
6 lines <6xl6ms
4 11 lines (l/6 page)
~11 x 16 ms
5
22 lines (l/3 page)
~22 x 16 ms
6 33 lines (l/2 page)
~33 x 16 ms
7
restores page 520 ms for 66 lines
The Line Printer printing and spacing instructions, iot series 65 and 66, are:
lpsf - 706501 - Skip if the printing flag is a 1.
lpcf - 706502 - Clear the printing flag.
lpld - 706542 - Load the Printing buffer.
lpse - 706506 - Select the Printer. Print the contents of the Printing buffer.
Clear the printing flag. (The printing flag becomes a 1 at
the completion of the printing.)
lssf - 706506 - Skip when the spacing flag becomes a 1.
lscf - 706602 - Clear the spacing flag.
ISIS - 706606 - Load the spacing buffer from AC bits 15-17 and select
spacing. Clear the spacing flag. (The spacing flag becomes
a 1 when spacing is complete.)
The printing and spacing flags are connected to the Program Interrupt
and to the iors instruction bits 15 and 16.
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