...and the correct answer is:
Yes! Marker display is generated on the Controller Board A2. If you are having Marker display issues (tail on marker), bring up the CRT adjustment screen. It should look exactly as the manual shows. Mine had the Digital X lines in a pretty big X, they are supposed to be parallel. The DGTL X GAIN pot was misadjusted AND intermittent. Cleaned, and adjusted again, problem resolved.