MODE 1

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Caterpillar (IJK, 1983)
Frak! (Aardvark, 1984)
"The Terrordactyls" (from Doctor Who: The First Adventure, BBC Soft, 198?)

MODE 1 is a medium-resolution screen MODE, introduced on the BBC Micro Model B and supported by the entire BBC series including the Archimedes. It allows colour graphics to be shown but leaves only 9 KB for programs -- even less if a disc interface or Econet is fitted.

MODE 1
Type Graphical ('ASCII')
Resolution Text 40 × 32 characters
Graphics 320 × 256 pixels
Character size 8 × 8 pixels, user definable
Pixel aspect 1:1 (square)
Bits per pixel 2
Default palette Logical colour Actual colour
0 0 (black)
1 1 (red)
2 3 (yellow)
3 7 (white)
Memory allocated 20480 bytes
on screen 20480 bytes
Address range Model B etc. &3000..&7FFF
Configuration Video ULA control register &D8
Video ULA palette register file &07 &17 &26 &36
&47 &57 &66 &76
&84 &94 &A0 &B0
&C4 &D4 &E0 &F0
CRTC register file &7F &50 &62 &28
&26 &00 &20 &22
&01 &07 &67 &08
(from table in MOS 1.20 at &C46E..&C479)

-- beardo 14:10, 16 September 2006 (BST)