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Re: apple ][ lo res mode colors?
Mad Scientist Jr wrote:
Is it true that in lo-res mode (what was the resolution? or was it just
40 column text?) the original Apple II could display 16 colors? What
colors were they?
Thanks
Lo-res mode colors:
0 - black
1 - red
2 - dark blue
3 - pink
4 - dark green
5 - dark gray
6 - mid blue
7 - light blue
8 - brown
9 - orange
10 - light gray
11 - apricot
12 - light green
13 - yellow
14 - aqua
15 - white
There are 40 pixels across, and 48 pixels down. This corresponds to the
text resolution of 40x24, since lo-res mode actually repurposes the same
RAM used by the text screens. Each text character corresponds to two
lo-res pixels stacked vertically (I'm not sure which nibble corresponds
to the upper and lower pixels). There are no restrictions to color
placement (unlike hi-res) since every pixel is true 4-bit color.
Most commonly you'll see a "mixed mode" which displays 40x40 color
pixels plus 4 lines of text at the bottom of the screen. This mode is
supported in Applesoft BASIC via the "GR" command. You can switch the
bottom four text lines into color pixels by PEEKing certain memory
locations (called softswitches) that change the display, but there is no
predefined BASIC command to do this. I say predefined because Applesoft
has a nifty feature that lets you code language extensions using the &
character. So, a very small machine language program and setting up some
vectors would allow you to code, say, &GR2 to set the full 40x48 lo-res
graphics. This is advanced Apple II programming, I haven't learnt how to
do it myself yet.
Sounds like you might enjoy downloading one of the many excellent Apple
II emulators (I use AppleWin on Windows) - just google for "Apple II
emulator". Craig Bower has written a very cool lo-res game called
SnakeByte that you might want to try out, as well as some other programs
that make great use of this neglected graphics mode.
http://www.turbo-2.com/apple (scroll to bottom)
Martin