Difference between revisions of "MODE 4"

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[[Category:Display]]
 
[[Image:Starship Command gameplay screenshot.png|right|''Starship Command'' (Acornsoft, 1983)]]
 
[[Image:Starship Command gameplay screenshot.png|right|''Starship Command'' (Acornsoft, 1983)]]
 
[[Image:Vortex gameplay screenshot.png|right|''Vortex'' (Software Invasion, 1983)]]
 
[[Image:Vortex gameplay screenshot.png|right|''Vortex'' (Software Invasion, 1983)]]
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|- style="vertical-align:top"
 
|- style="vertical-align:top"
 
| Video ULA palette register file
 
| Video ULA palette register file
| &07 &17 &27 &37<br> &47 &57 &67 &77<br> &80 &90 &A0 &B0<br> &C0 &D0 &E0 &F0
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| &07 &17 &27 &37 &47 &57 &67 &77<br> &80 &90 &A0 &B0 &C0 &D0 &E0 &F0
 
|- style="vertical-align:top"
 
|- style="vertical-align:top"
 
| [[CRTC]] register file
 
| [[CRTC]] register file
| &3F &28 &31 &24<br> &26 &00 &20 &22<br> &01 &07 &67 &08<br> (from table in [[MOS 1.20]] at &C486..&C491)
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| &3F &28 &31 &24 &26 &00<br> &20 &22 &01 &07 &67 &08<br> (from table in [[MOS 1.20]] at &C486..&C491)
 
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|}
 
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{{MODE}}
 
-- [[User:Beardo|beardo]] 14:13, 16 September 2006 (BST)
 
-- [[User:Beardo|beardo]] 14:13, 16 September 2006 (BST)
[[Category:Display]]
 

Latest revision as of 19:22, 12 October 2016

Starship Command (Acornsoft, 1983)
Vortex (Software Invasion, 1983)
Tomcat (Players, 1989)

MODE 4 is a medium-resolution screen MODE, introduced on the BBC Micro Model A and supported by the entire BBC series including the Archimedes. It allows detailed graphics to be shown while leaving 15 KB or more free for programs; however to achieve this the display is made monochrome.

In Elite and Revs a custom interrupt routine splits the screen in two; the top half is configured as MODE 4 to show the exterior view in detail.

MODE 4
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 1
Default palette Logical colour Actual colour
0 0 (black)
1 7 (white)
Memory allocated 10240 bytes
on screen 10240 bytes
Address range Model B etc. &5800..&7FFF
Configuration Video ULA control register &88
Video ULA palette register file &07 &17 &27 &37 &47 &57 &67 &77
&80 &90 &A0 &B0 &C0 &D0 &E0 &F0
CRTC register file &3F &28 &31 &24 &26 &00
&20 &22 &01 &07 &67 &08
(from table in MOS 1.20 at &C486..&C491)
Screen display MODEs

MODE 0 | MODE 1 | MODE 2 | MODE 3 | MODE 4 | MODE 5 | MODE 6 | MODE 7
MODE 8 | MODE 9 | MODE 10 | MODE 11 | MODE 12 | MODE 13 | MODE 14
MODE &60 | MODE &61 | MODE &63 | MODE &64 | MODE &66
MODE &68 | MODE &69 | MODE &6B | MODE &6C | MODE &6E
MODE | VDU 22

-- beardo 14:13, 16 September 2006 (BST)