Video Data Wrap Test for a CRT Display
Original Publication Date: 1983-Oct-01
Included in the Prior Art Database: 2005-Feb-07
A known character sequence is sent to a display. A function of the serialized video data is compared to a precalculated value for that sequence to check for errors. This allows all of the display circuitry to be tested, even when the CRT itself is hors de combat or unreadable. (Image Omitted) Fig. 1 shows a typical display terminal 10 having data, address, and control bus 11 coupling together a microprocessor 12, ROM (read-only memory) and RAM (random-access memory) memory 13, adapters 14 for communications, keyboard, etc., and a display adapter 15 having serial red (R), green (G), and blue (B) video outputs to a color CRT 16. Test adapter 20 is coupled to the R, G. B. video outputs and to system buses 11. In Fig.