Browse Prior Art Database

SOFTWARE ELECTRONIC SUB-SYSTEM

IP.com Disclosure Number: IPCOM000025840D
Original Publication Date: 1988-Jun-30
Included in the Prior Art Database: 2004-Apr-04
Document File: 4 page(s) / 175K

Publishing Venue

Xerox Disclosure Journal

Abstract

A hardware electronic sub-system is currently utilized in non-impact printers such as the Xerox 4045TM laser printer to generate an image based on the alphanumeric character to be printed, the desired font, and the character size. The electronics to implement this function, particularly where other imaging parameters such as proportional spacing, rightlleft justification, and image orientation are included, is quite sophisticated and very expensive to manufacture.

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Page 1 of 4

EROX DISCLOSURE JOURNAL

SOFTWARE ELECTRONIC

Douglas A. Ross Mark Zachman

SUB-SYSTEM

Proposed Classification

U.S. C1.355/14 Int. C1. G03g 15/00

-

FlG. I

I

,

Volume 13 Number 3 May/June 1988 157

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Page 2 of 4

SOFTWARE ELECTRONIC SUB-SYSTEM (Cont'd)

CONTROL CONTROL

FIG. 2

 XEROX DISCLOSURE JOURNAL Volume 13 Number 3 May/June 1988

158

[This page contains 1 picture or other non-text object]

Page 3 of 4

SOFTWARE ELECTRONIC SUB-SYSTEM (Cont'd)

A hardware electronic sub-system is currently utilized in non-impact printers such as the Xerox 4045TM laser printer to generate an image based on the alphanumeric character to be printed, the desired font, and the character size. The electronics to implement this function, particularly where other imaging parameters such as proportional spacing, rightlleft justification, and image orientation are included, is quite sophisticated and very expensive to manufacture.

Many customers have personal computers (PC's), the majority of which are IBM compatible, that are used to provide an input to the customers' printer. The software electronic sub-system described here utilizes the customers' own PC to provide the same capability as a hardware electronic sub-system but without the associated cost.

The software electronic sub-system described and depicted in Figures 1 and 2 of the drawings is an integrated software and hardware system, with the hardware consisting of a printed circuit interface board 4 which is pluggable into a full width expansion slot of the host PC 3. The software is a stand alone application program which runs under MS-DOS. The cost of the software electronic sub-system, including printed circuit board 4, FCC qualified inter- connecting cable, software license, diskette, and packaging is much less than the manufacturing cost of the hardware electronic sub-system. This results in a substantial saving for a customer who purchases a printer without a hardware electronic sub-system over a customer who purchases the same printer with a hardware electronic sub-system.

The main function of the printed wiring board 4 is to allow the PC 3 to transmit high speed (i.e., 2.25 M bits/second) video data to the printer 2 and yet maintain com atibility with all the PC's which claim IBM compatibility. This is accomplis

     R ed by mapping the printed wiring board 4 into the PC's memory space and using the appropriate software to maximize the transfer rate. Interrupt lines or DMA channels are avoided since the interrupt and DMA signals and are most likely to differ from one PC to another.

Data transfer is aided by two sequentially accessed band buffers 7, 8 which operate in a ping pong manner. T...