18 Jan
2006
18 Jan
'06
11:43 a.m.
There is a bit of a spat going on in a few forums
regarding color index
#6 of IBM CGA. The old-timers know that it is brown from experience and
existing working hardware; the newbies (writing or using emulators) are
unwilling to accept that and are instead making CGA palettes with dark
yellow instead of brown.
Can anyone give me the history on why #6 is brown? Was it a design
mistake, or intentional? Is it a property of the monitor or something?
I can't find anything of substance to offer the newbies to convince them
otherwise; digital photos can be accused of being doctored or
miscalibrated (and yet is a digital photo showing "yellow" that started
this whole thing). About the only thing I can think of to offer as
proof is that the text colors in the VGA palette show brown, and IBM
wouldn't have done something like that by mistake -- or were they
perpetuating a mistake?
My recall of the color pallete in CGA mode was that the
"dark" versions of
the main colors were a bit flip from the main colors and that "brown"
really was "dark yellow." You could call it dark yellow all you wanted
(and some docs did) but once painted on the screen, it was brown. I think
white with the corresponding bit set (cleared?) was gray. Or was dark gray
equivalent to black...? I forget. I recall that something about it was
logically wierd and didn't make sense.
I have some docs at home I should dig through and see if I can find this.
Paper docs are much less subject to later revision than google searches...
-T