17 Nov
2007
17 Nov
'07
9:53 p.m.
On 17 Nov 2007 at 11:26, Chris M wrote:
Off the top of my head, I don't know, or rather
can't
see what a prom had to do with it. If a monitor's
phosphors were capable of producing brown (presumably
all were) and the unit is *tuned* to take a *brown*
signal and display brown, you'd have brown. But I
guess I'll have to look over those posts (~2.5 years
ago IIRC).
The EGA had the prom; without consulting my O&A for the CGA version,
it might have been some TTL logic rather than a ROM. The situation
goes this way. If rgb are "normal level" red, green and blue signals
and RGB is "intensified", dark yellow is r+g; brown is r+1/2g and
bright yellow is RG. To get brown, you need logic in the monitor to
drop the green level to one-half "normal" brightness only when the
brown combination is detected. Otheriwse, if you simply tune down
the green level by half for all colors, everything suffers.
Cheers,
Chuck