Browse Prior Art Database

Serial Printer Emulation

IP.com Disclosure Number: IPCOM000078156D
Original Publication Date: 1972-Nov-01
Included in the Prior Art Database: 2005-Feb-25
Document File: 4 page(s) / 93K

Publishing Venue

IBM

Related People

Powers, JT: AUTHOR

Abstract

Programs which store and manipulate data originated at keyboard/serial printer terminals making use of format effector characters (such as backspace, index, and carriage return), must reformat this data before printing it on a printer which does not accept such format effector characters. The flow chart of the figures describes an algorithm which will perform such a conversion and printing operation for data, which contains any number of levels of overprinting via backspacing. Also processed in such a manner that printed output is identical to that produced by a serial printer are the index, carriage return (new line), and idle characters. Variable names used in the flow chart and their significance are: Input Variables B An array of single-character elements which contains the data to be printed.

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Serial Printer Emulation

Programs which store and manipulate data originated at keyboard/serial printer terminals making use of format effector characters (such as backspace, index, and carriage return), must reformat this data before printing it on a printer which does not accept such format effector characters. The flow chart of the figures describes an algorithm which will perform such a conversion and printing operation for data, which contains any number of levels of overprinting via backspacing. Also processed in such a manner that printed output is identical to that produced by a serial printer are the index, carriage return (new line), and idle characters. Variable names used in the flow chart and their significance are: Input Variables
B An array of single-character elements which contains the data to be printed.

LB A scalar, whose value is the number of elements of B to be printed.

Work Variables and Symbolic Constants

P An array of single-character elements, in which the output characters are assembled for printing.

LP A scalar, whose value is the number of elements in P and also the number of print positions

available on the line printer.

SPX A scalar, whose value is the maximum number of print lines by which the line printer carriage may be

advanced in one print or skip command.

BINDEX Index into the array B; 1 < BINDEX < (LB + 1) PINDEX Index into the array P; 1 < INDEX < (LP r 1) PNEXTSAVE )

PXSAVE ) Temporary storage for important indices into the P and B arrays.

BXSAVE )

REPRNTSW A binary switch which records whether or not at least one level of overprinting remains.

DONESW A binary switch which records whether or not all of the characters in B have been processed.

TSKIP Temporary storage for the count of lines to be skipped in the next print operation.

Miscellaneous MIN Name of a function which returns the smaller of two input variables.

The algorithm of the figures first scans the B array...