Extra Half-Brite

E736622

Extra Half-Brite is a special Amiga display mode that allows 64-color graphics by using an additional bitplane to show dimmed versions of 32 base colors.

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Statements (41)

Predicate Object
instanceOf Amiga display mode
computer graphics display mode
advantage allows shading and lighting effects via half-bright colors
doubles apparent color count with minimal memory increase
alsoKnownAs EHB NERFINISHED
Extra-Halfbrite mode NERFINISHED
baseColorCount 32
bitplaneCount 6
category Amiga graphics technology
bitplane graphics mode
colorDepth 6-bit RGB equivalent
colorModel indexed color
colorSelection 32 freely selectable base palette entries
derivedColorMechanism hardware halves RGB values when extra bitplane is set
documentation described in Amiga Hardware Reference Manual
era late 1980s home computer graphics
extraBitplanesUsedFor half-brightness flag
halfBrightColorCount 32
halfBrightColorsDerivedFrom 32 base colors
halfBrightComputation performed in hardware, not in software
halfBrightIntensity approximately 50% of base color intensity
hardwareSupport ECS NERFINISHED
OCS NERFINISHED
implementedBy Amiga Agnus and Denise custom chips
introducedWith original Amiga 1000 era chipsets
memoryCostComparedTo32Color requires one additional bitplane
paletteLimit 32 independent color registers
paletteSource Amiga custom chipset color registers
platform Commodore Amiga NERFINISHED
relatedMode HAM (Hold-And-Modify) NERFINISHED
standard 32-color Amiga mode
renderingCharacteristic half-bright colors always tied to corresponding base palette entries
requires 6th bitplane set as extra-halfbrite plane
supports up to 64 simultaneous on-screen colors without HAM
totalColorCount 64
typicalUse demos
games
graphics applications
usedIn Amiga demo scene productions
Amiga games with detailed backgrounds
usesBitplanes yes

Referenced by (1)

Full triples — surface form annotated when it differs from this entity's canonical label.

Original Amiga chipset (OCS) supportsMode Extra Half-Brite
subject surface form: Original Amiga chipset