Preventing CGA revisionist history
Eric J Korpela
korpela at ssl.berkeley.edu
Wed Jan 25 20:39:34 CST 2006
Since I'm seeing this 6 days late, I'd guess it was answered already.
On the off hand that it hasn't been answered....
> regarding the CGA, the technical manual mentions a 160x200 mode with
> more that 4 colors. It doesn't give any more information on how to
> enable this mode, though.
You mean 160x100, no? The 160x100 mode is an 80x100 color text mode
using graphics character 221 (left half on) or 222 (right hand on).
You get it by altering the text height register so the text is reduced
to two scan lines per row. In essence you fill the screen with
character 221 and modify the text attributes (foreground and
background color) to set the pixel colors.
I suppose it might be possible to get 160x200 on a CGA clone with 32K
of RAM rather than 16K. Most "extended CGA" clones came with their
own special graphics modes.
Here's some screen shots of a game that uses 160x100 mode.
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