Amiga color, palette and image formats

As for a new project i have in mind, a text adventure with graphics like the magnetic scrolls series, I’m thinking about the image and color/palette formats the various amiga models use and handle.

The Amiga “Denise” chip is responsible for the graphical capabilities of the OCS/ECS amigas. That is the MOS 8362 “Denise” for OCS or MOS 8370 “Hires/ECS Denise” for ECS.

Amiga “Agnus” chip is responible for controlling the ChipRAM, DMA, resource management, video signals, copper and blitter.
See an “Agnus” table of various versions here.

For the 1992 upcoming AGA chipset both chips got renamed:

“Denise” => “Lisa”
“Agnus” => “Alice”

OCS (Original Chip Set)

  • MOS 8362 “Denise”, MOS 8370/8371 “Agnus”
  • Earliest Amiga models 1985-1990
    A500, A1000, A1500 (an UK specific A2000 derivate), A2000
  • Kickstart 1.0+
  • Palette of 4096 colors (12bit)
  • Adressing up to 512kB ChipRAM

ECS (Enhanced Chip Set)

  • MOS 8373 “Hires/ECS Denise”, MOS 8372-A/B or MOS 8375 “Agnus”
  • Later Amiga models 1990+
    A3000, A500+, A600 and upgrade kits for older models.
  • Kickstart 2.0+
  • Palette of 4096 colors (12bit)

Additional features over OCS:

  • Adressing 1MB/2MB ChipRAM with appropriate “Agnus”
  • Display resolutions like OCS plus:
    • Productivity Mode (640x480x4 non-interlaced)
    • SuperHires Mode (1280x256x4 non-interlaced / 1280x512x4 interlaced)
  • Blitter copies regions larger than 1024×1024
  • Display sprites in border regions

AGA (Advanced Graphics Architecture)

  • MOS 8364 “Lisa” chip, formerly “Denise”
    MOS 8374 “Alice” chip, formerly “Agnus”
  • Introduced 1992, first use in A4000, later A1200 (1992) and CD32 (1993)
  • Kickstart 3.0+

Additional features over ECS:

  • Adressing up to 2MB ChipRAM
  • Palette of 16777216 colors (24bit)
  • Display resolutions like ECS plus:
    • 256 colors in every indexed display mode
    • 262144 colors in HAM-8 modes
  • Super Hires smooth scrolling
  • 32bit fast page memory for 8bitplanes graphics modes
  • Wider sprites

ToDo:

  • Overview table
  • EHB modes
  • Example Pictures
Advertisements
  1. No trackbacks yet.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: