Browse Prior Art Database

COM File Execution on Typewriter

IP.com Disclosure Number: IPCOM000035093D
Original Publication Date: 1989-Jun-01
Included in the Prior Art Database: 2005-Jan-28
Document File: 2 page(s) / 13K

Publishing Venue

IBM

Related People

Combs, JL: AUTHOR [+2]

Abstract

This disclosure describes a method to allow execution of an IBM PC* computer COM file to be executed on a typewriter. This method involves adding a 256 byte header to the front of the COM file. This header contains information for the typewriter to identify the COM file as a typewriter document. It also contains a small start-up routine which may or may not be needed, depending on the method used to create the COM file.

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COM File Execution on Typewriter

This disclosure describes a method to allow execution of an IBM PC* computer COM file to be executed on a typewriter. This method involves adding a 256 byte header to the front of the COM file. This header contains information for the typewriter to identify the COM file as a typewriter document. It also contains a small start-up routine which may or may not be needed, depending on the method used to create the COM file.

The operator interface used at the typewriter to invoke this document is PLAY + '=' + '0'. The typewriter checks to see if there is a document on the diskette named 'DOCUMO##.TXT'. This document, if it exists, is loaded into typewriter storage. A far call is made to location 48H to execute this document. On return, the AL register is checked to see if this document is to remain in storage or be deleted. If AL is zero, the document is deleted from storage and normal typewriter operation resumes. If AL is not zero, the document is left in memory and normal typewriter operation continues. This allows for programs to hook into the typewriter and stay resident after the initial load operation. At the present time, there are no resident programs planned for this machine. This document shows up as ?????? on the typewriter directory.

There are some limitations to this method. Programs written to run on the IBM PC expect DOS to be resident and use DOS calls to access the PC input and output devices. These do not exist on the typewriter. There are interrupts that can be used to access the various input and output devices of the typewriter. Therefore, programs that are written for the PC will not work on the typewriter and programs written for the typewriter will not run on the PC. This method takes advantage of a large installed base of PCs that can be used to create COM files which, in turn,...