FYI, tri sync = standard, medium and high resolutions.... also called 15k, 25k, and 31k also often erroneously called "CGA" "EGA" and "VGA" (well not VGA anyways)
15k = 640x240 "CGA" or standard resolution
25k = 773x381 "EGA" or medium resolution (AKA "good fer nothin res")
31k = 640x480 VGA or high resolution
38k = 800x600 SVGA or often erroneously called "XGA" (not widely implemented in arcade due to the movement away CRT and towards FPD's and TV's as output devices)