- Improve resolution of ColorClassic builtin Display -

Why possible to display 640x480 pixel?

Hardware specification of ColorClassic series is LC series base, and 640x480 pixel diaplay is possible in each base model either.
Because I judge the control signal line called "MONITOR SENSE LINE" in Macintosh and distinguish and MONTOR TYPE, I judge logic board at least if coax this place when "Display is 13 inches".
There is the main problem to a built-in display.
The built-in display of ColorClassic is 10-inchs TRINITRON CRT display, this designed as single resolution display compatible with original 12 inches color display, 24.48 kHz, the vertical frequency and 60.15 Hz the horizontal frequency.
But 13-inchs Display is horizontal frequency 35.0 kHz, vertical frequency 66.67 Hz.
So, it solved this problem by up the horizontal scan voltage to 84V from 60V.