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Data Entry Terminal Having Keyboard Selectable Off-Line Diagnostics

IP.com Disclosure Number: IPCOM000050174D
Original Publication Date: 1982-Sep-01
Included in the Prior Art Database: 2005-Feb-10
Document File: 3 page(s) / 50K

Publishing Venue

IBM

Related People

Heikel, HH: AUTHOR [+4]

Abstract

A microprocessor controlled color display terminal contains microcode for taking the terminal off-line from its host computer and performing a number of selectable diagnostic functions. Off-line mode and individual functions are controlled directly from the terminal keyboard, without any special switches or other controls.

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Data Entry Terminal Having Keyboard Selectable Off-Line Diagnostics

A microprocessor controlled color display terminal contains microcode for taking the terminal off-line from its host computer and performing a number of selectable diagnostic functions. Off-line mode and individual functions are controlled directly from the terminal keyboard, without any special switches or other controls.

Terminal 10 is organized around bus 11. Microprocessor 12, read only storage 13 for microcode, and read-write working storage are coupled to the bus. Communications adapter 15 connects terminal 10 to a host computer. Conventional buffer 16 refreshes the screen of raster scan CRT display 20. I/O adapters 17 interface keyboard 21 as well as other peripheral devices, such as light pen 22 and badge reader 23.

Microcode in storage 13 causes microprocessor 12 to recognize the simultaneous depression of CMD-RST (keys labeled "Command" and "Reset") on keyboard 21 as a signal to enter off-line select mode when terminal 10 is in its power-on sequence; if already powered up, CMD-RST first enters the terminal into on-line select mode and then the 0 and ENTER keys must also be struck in succession. Once in off-line select mode, several independent diagnostic functions can be initiated by pressing CMD and an alpha key. Several examples follow.

CRT test patterns consist of a full screen box divided by a vertical and horizontal center line. The test screen is used to adjust centering, check and adjust pincushion, adjust width, height, and skip.

CMD-F selects the alignment screen.

CMD-H, CMD-J, CMD-K display reverse image red, green and blue screens, respectively, for the purpose of adjusting color purity.

CMD-G selects a screen filled with red 0 characters used to adjust focus.

CMD-D selects a screen with 7 horizontal color bars used to adjust color balance.

CMD-V displays the scan codes of depr...