18 Jan
2006
18 Jan
'06
9:04 a.m.
Brown was really brown on an IBM display anyway. It wasn't just a
darker color as other people had suggested. The cheaper rip off
monitors typically did not do "true" IBM brown. Why IBM made this a
design requirement, I have no idea. If I have time, I will analyze
Correct. One thoguht : There is nothing I can see that particularly
detects colour 6 in the NTSC encoder on the CGA card itself. So, what
does a composite monitor display for colour 6? Dark Yellow, or Brown? Was
the mod to the 5153 monitor done to make it agree with the display on a
compositie monitor?
the IBM color CGA monitor schematics I have. IBM went
to a LOT of
trouble to combine signals for I, B, at 0 and R and G at 1 to get Brown.
For 'LOT of trouble', read : 4 open-collector NOT gates (but 2 '05s were
needed anyway to provide 8 gates to buffer the signals), 1 transistor,
and a handful of passives.
-tony