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Independent Self-Test of Printer Bit-Image-Graphics Capability

IP.com Disclosure Number: IPCOM000062530D
Original Publication Date: 1986-Dec-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 3 page(s) / 56K

Publishing Venue

IBM

Related People

Danner, DR: AUTHOR

Abstract

A user can verify graphics performance of a printer independently of its host computer. This should lead to a reduction in service calls in which no trouble is found. When a user of a printer performs a self- test through activating certain keys, a special line appears in the output. This special line consists of four colons with each colon contained inside a small box and the four boxes being spaced equal distances from each other. If any colon lies outside of its box, the user will be instructed to have the printer serviced. The printer, which has forty electrodes arranged in a column, responds to six commands as described in U.S. Patent 4,467,363, with four being used to completely exercise the graphics ability of the printer.

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Independent Self-Test of Printer Bit-Image-Graphics Capability

A user can verify graphics performance of a printer independently of its host computer. This should lead to a reduction in service calls in which no trouble is found. When a user of a printer performs a self- test through activating certain keys, a special line appears in the output. This special line consists of four colons with each colon contained inside a small box and the four boxes being spaced equal distances from each other. If any colon lies outside of its box, the user will be instructed to have the printer serviced. The printer, which has forty electrodes arranged in a column, responds to six commands as described in U.S. Patent 4,467,363, with four being used to completely exercise the graphics ability of the printer. These four commands are the following: offset from base, map bit for bit, repeat column, and black in sequence and complete white. Each command/data byte consists of three command bits and five data bits sent serially to the Print Electronics. Proper operation can be verified by individually setting and then clearing each bit of the command/data sequence. To generate the test line, the following operations/commands are sent sequentially to the Print Electronics: 1. Using the font to which the machine defaults when turned on, colons are printed at selected, equally

spaced print positions, beginning at the left margin

character position. 2. A carrier return is sent to the Print Electronics. 3. Graphic mode is now entered to "draw" a box around each colon in accordance with the steps shown in the

drawing. 4. The first box is "drawn" by the following

command/data sequence: bottom

b. map 5 ;map next 5 bytes directly to printhead

c. data (5 bytes) ;builds left side of box

d. repeat 2 ;makes left side of box 3 columns wide

e. map 5 ;map next 5 bytes directly to printhead

f. data (5 bytes) ;build top and bottom of box

g. repeat x ;sets width of box, pitch dependent*

h....