ANTIC (AlphaNumeric Television Interface Controller) reference

ANTIC register set:
    7 6 5 4 3 2 1 0
$D400 (W)DMACTL unused DL DMA PM Res. P DMA M DMA Playfield Width
$D401 (W)CHACTL unused Turned Inverse Opaque
$D402 (W)DLISTL Display List Low (A7-A0)
$D403 (W)DLISTH Display List High (A15-A8)
$D404 (W)HSCROL unused Horizontal Scrolling
$D405 (W)VSCROL unused Vertical Scrolling
$D406 (W)  unused
$D407 (W)PMBASE Player/Missile Base High (A15-A10) unused
$D408 (W)  unused
$D409 (W)CHBASE Character Set Base High (A15-A9) unused
$D40A (W)WSYNC unused
$D40B (R)VCOUNT Vertical Line Counter / 2
$D40C (R)PENH Horizontal Light Pen Trigger Position
$D40D (R)PENV Vertical Light Pen Trigger Position
$D40E (W)NMIEN DLI VBI Reset unused
$D40F (R)NMIST DLI VBI Reset unused ¹
$D40F (W)NMIRES unused

¹ - Unused bits read back 1

ANTIC instruction set:
  7 6 5 4 3 2 1 0
Blank Line DLI Number of scan lines to skip - 1 0
Mode Line DLI LMS VScroll HScroll ANTIC Mode (2-15)
Jump DLI 0 unused $1
Jump/Wait for VBL DLI 1 unused $1

ANTIC display modes:
Mode Resolution Colors Mode Height Pixel Height
2 320*192 2 (Monochrome) 8 1
3 320*192 2 (Monochrome) 10 1
4 160*192 5 (4 per char) 8 1
5 160*96 5 (4 per char) 16 2
6 160*192 5 (2 per char) 8 1
7 160*96 5 (2 per char) 16 2
8 40*24 4 8 8
9 80*48 2 (Monochrome) 4 4
10 80*48 4 4 4
11 160*96 2 (Monochrome) 2 2
12 160*192 2 (Monochrome) 1 1
13 160*96 4 2 2
14 160*192 4 1 1
15 320*192 2 (Monochrome) 1 1
GTIA 1 (15) 80*192 16 Lumas/1 Chroma 1 1
GTIA 2 (15) 80*192 9 1 1
GTIA 3 (15) 80*192 1 Luma/16 Chromas 1 1

Resolutions are based on a standard display field size. By using other display field sizes, different amounts of pixels are displayed. Please note that vertical resolutions of bitmap modes can easily be reduced by using LMS in display lists. This also makes modes 11 and 13 redundant, since the same resolutions can be achieved by using modes 12 and 14 plus a display list using LMS.


© 2009-2012 Graham

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