====== GIME PALETTE ======
The Color Computer 3 video chip, known as the GIME supports display of up to 16 simultaneous colors out of a palette of 64, much like the [[wp>EGA]] graphics adapter for IBM PC-compatibles.

{{:tandy_color_computer:64colors-cmp.png?direct&400|64 Colors Composite}}
{{:tandy_color_computer:64colors-rgb.png?direct&400|64 Colors RGB}}

===== PROGRAMMING =====
Super Extended BASIC has the following commands: \\
  * **PALETTE CMP**
    * Sets all 16 palette slots to Super Extended BASIC's list of Composite default values
  * **PALETTE RGB**
    * Sets all 16 palette slots to Super Extended BASIC's list of RGB default values
  * **PALETTE //palette register//, //color code//**
    * Sets palette register 0-15 to color code 0-63

The 16 active palette entries are programmed through GIME memory-mapped registers $FFB0 to $FFBF

===== DEFAULT PALETTES =====

==== BOOT ====

On boot, all palette registers are initialized to Green ($12) by code in $C006 - $C011.

Next, the following values are loaded into the CoCo 3 Palette Registers from PALIMAGE ($C236 - $C245) by code in $C04E - $C05F, after the boot code is moved down to $4xxx.

This color map defaults to Composite colors for use with televisions or monitors connected through RF Out or Composite Out.

==== PALETTE COLOR SETS ====
The boot palette colors are duplicated in memory at IM.CMP ($E654 - E663) which is loaded by the PALETTE CMP command.

The composite color set are again duplicated in memory at IM.PALET ($E678 - $E687) which is used as the "current palette" set by the PALETTE <palette register 0-15>, <color code 0-63> command.

For RGB or PAL, the colors are loaded by the PALETTE RGB command from IM.RGB ($E664 - $E673) table.

For CoCo compatibility, the RGB color set should be loaded on initialization for PAL version.

^ Register ^ Color Name ^ Composite Palette Code ^ RGB/PAL Palette Code ^
| $FFB0 | Green | $12 | $12 |
| $FFB1 | Yellow | $24 | $36 |
| $FFB2 | Blue | $0B | $09 |
| $FFB3 | Red | $07 | $24 |
| $FFB4 | Buff | $3F | $3F |
| $FFB5 | Cyan | $1F | $10 |
| $FFB6 | Magenta | $09 | $2D |
| $FFB7 | Orange | $26 | $26 |
| $FFB8 | Black | $00 | $00 |
| $FFB9 | Green | $12 | $12 |
| $FFBA | Black | $00 | $00 |
| $FFBB | Buff | $3F | $3F |
| $FFBC | Black | $00 | $00 |
| $FFBD | Green | $12 | $12 |
| $FFBE | Black | $00 | $00 |
| $FFBF | Orange | $26 | $26 |

===== PALETTES BY MODE =====
^ [[VDG]] Alphanumeric ^ Palette Registers Used ^ Palette Register Address ^
| 32 x 16 Background | 13 | $FFBD |
| 32 x 16 Foreground | 12 | $FFBC |

^ [[VDG]]  Semigraphics ^ Palette Registers Used ^ Palette Register Address ^
| SG4 | FIXME | FIXME |
| SG6, CSS=0 | FIXME | FIXME |
| SG6, CSS=1 | FIXME | FIXME |
| SG8 | FIXME | FIXME |
| SG12 | FIXME | FIXME |
| SG24 | FIXME | FIXME |

^ [[VDG]] Graphics ^ Palette Registers Used ^ Palette Register Address ^
| CG1, CSS=0 | 0-3 | $FFB0 - $FFB3 |
| CG1, CSS=1 | 4-7 | $FFB4 - $FFB7 |
| RG1, CSS=0 | 8,9 | $FFB8, $FFB9 |
| RG1, CSS=1 | 10,11 | $FFBA, $FFBB |
| CG2, CSS=0 | 0-3 | $FFB0 - $FFB3 |
| CG2, CSS=1 | 4-7 | $FFB4 - $FFB7 |
| RG2, CSS=0 | 8,9 | $FFB8, $FFB9 |
| RG2, CSS=1 | 10,11 | $FFBA, $FFBB |
| CG3, CSS=0 | 0-3 | $FFB0 - $FFB3 |
| CG3, CSS=1 | 4-7 | $FFB4 - $FFB7 |
| RG3, CSS=0 | 8,9 | $FFB8, $FFB9 |
| RG3, CSS=1 | 10,11 | $FFBA, $FFBB |
| CG6, CSS=0 | 0-3 | $FFB0 - $FFB3 |
| CG6, CSS=1 | 4-7 | $FFB4 - $FFB7 |
| RG6, CSS=0 | 8,9 | $FFB8, $FFB9 |
| RG6, CSS=1 | 10,11 | $FFBA, $FFBB |

^ [[GIME]] Alphanumeric ^  Palette Registers Used ^ Palette Register Address ^
| 32, 40, 64, 80 Background | 0-7 | $FFB0 - $FFB7 |
| 32, 40, 64, 80 Foreground | 8-15 | $FFB8 - $FFBF |

^ [[GIME]] Graphics ^  Palette Registers Used ^ Palette Register Address ^
| 2-Color | 0 - 1 | $FFB0 - $FFB1 |
| 4-Color | 0 - 3 | $FFB0 - $FFB3 |
| 16-Color | 0 - 15 | $FFB0 - $FFBF |

===== VIDEO =====
[[https://www.youtube.com/watch?v=gc6Eu7IansE|NTSC 8-bit Color on the Color Computer 3]] \\
[[https://www.youtube.com/watch?v=42jBBrqn70w|CoCo3 Video Player Version 2 Demo]]

===== REFERENCES =====
[[http://users.axess.com/twilight/sock/gime.html|Sockmaster's GIME Register Reference]] \\
[[https://github.com/mamedev/mame/blob/master/src/mame/video/gime.cpp|MAME GIME Source]] - Composite Palettes as hex codes \\
[[http://exstructus.com/coco/australia-colour-palette/|CoCo 3 Australia Color Palette]] - Palettes compared

===== SEE ALSO =====
[[https://archive.org/details/TandyServiceManualColorComputer3/|Color Computer 3 Service Manual]] \\
[[https://colorcomputerarchive.com/files/Documents/Books/Coco%20III%20Secrets%20Revealed%20(Microcom%20Software).pdf|CoCo3 Secrets Revealed]] by Microcom Software, 1986 \\
[[https://archive.org/details/Assembly_Language_Programming_for_the_CoCo_3_1987_Laurence_A_Tepolt/|Assembly Language Programming for the CoCo3]] by Lawrence Tepolt, 1987 \\
[[https://archive.org/details/Super_Extended_Basic_Unravelled_II_1999_Spectral_Associates/|Super Extended BASIC Unravelled]] by Spectral Associates/Walter Zydhek, 1999 \\

===== RTS =====
Return to [[:Tandy Color Computer:]] or [[Super Extended BASIC]]