x68000:vidcon_registers
Overview
Address | Size | Name | Description |
---|---|---|---|
$E82000 | 256.w | – | Graphic palette |
$E82200 | 256.w | – | Text palette, Sprite+BG palette |
$E82400 | 1.w | R0 | Screen mode |
$E82500 | 1.w | R1 | Priority control |
$E82600 | 1.w | R2 | Layer ON/OFF control/Special priority |
Graphic palette($e82000):
The structure of the graphic palette in 16/256 color mode and 65535 color mode.
16 color display: The first 16 words are used, the value read from the palette is directly output as a color code. 256 color display: The first 256 words are used, the value read from the palette is directly output as a color code. 65536 color display: In the text palette and the graphic palette in the 16/256 color display mode, the color codes of one word are arranged by the number of colors. However, in the 65536 color display mode the color codes are divided into upper/lower byte units. Two pairs of 256 bytes that are juxtaposed(upper/lower). When color codes are output, the data of G-VRAM is divided into upper byte and lower byte, each of which is independently determined and then synthesized.
PH = Upper byte of G-VRAM data PL = Lower byte 〃 CH = Upper byte of color code to be output CL = Lower byte 〃
CH = *(unsigned char)($E82002+PH×2-PH&1) CL = *(unsigned char)($E82000+PL×2-PL&1)
address size CH CL $E82000 1.b -- PL = $00 $E82001 1.b -- PL = $01 $E82002 1.b PH = $00 -- $E82003 1.b PH = $01 -- $E82004 1.b -- PL = $02 $E82005 1.b -- PL = $03 $E82006 1.b PH = $02 -- $E82007 1.b PH = $03 -- …… …… $E821F8 1.b -- PL = $FD $E821F9 1.b -- PL = $FD $E821FA 1.b PH = $FC -- $E821FB 1.b PH = $FD -- $E821FC 1.b -- PL = $FE $E821FD 1.b -- PL = $FF $E821FE 1.b PH = $FE -- $E821FF 1.b PH = $FF -- ($E82000 は PL = $00 の時の CL の値、と読むこと)
Text palette($e82200):
The text palette and the sprite+BG palette are 16 rows of 16 words and some are shared. The first palette block, 0, is used by the text palette and the value read from the palette is used as it is.
Sprite+BG palette($e82200):
Unlike the text palette, you can use all of the palette blocks 0 to 15. The PCG data contains value of the lower 4 bits, the data of the sprite scroll register and the BG data area contains value of the upper 4 bits.
Detail
<BOOKMARK:r0> VC R0($e82400):
bit 15 3 2 1 0 ┌─────────────────────────┬─┬───┐ │ │ │COL│ └─────────────────────────┴─┴───┘ SIZ
bit 2 SIZ GVRAM size %0 : 512× 512 pixels %1 : 1024×1024 pixels bit 1~0 COL Color mode %00 : 16 color %01 : 256 color %10 : Undefined %11 : 65536 color ※Set the same value bits as bits 10~8 of CRTC R20.
<BOOKMARK:r1> VC R1($e82500):
bit 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 ┌───┬───┬───┬───┬───┬───┬───┬───┐ │ │SP │TX │GR │GP3│GP2│GP1│GP0│ └───┴───┴───┴───┴───┴───┴───┴───┘
bit 13~12 SP Sprite screen priority bit 11~10 TX Text 〃 bit 9~ 8 GR Graphic 〃 bit 7~ 6 GP3 Page number of the 4th highest priority graphic screen bit 5~ 4 GP2 3rd 〃 bit 3~ 2 GP1 2nd 〃 bit 1~ 0 GP0 1st 〃
※SP/TX/GR use %00/$01/$10 to increase the screen priority. ※When the graphic screen is 1 page, GP3~GP0 are handled as one set. In case of 2 pages, GP3~GP2/GP1~GP0 are handled as one set each. ※GP3~GP0 setting value 65536 colors : %1110_0100 256 colors : %1110_0100(page 1 < page 0) %0100_1110(page 0 < page 1) 16 colors : %1110_0100(page 3 < page 2 < page 1 < page 0) … %0001_1011(page 0 < page 1 < page 2 < page 3)
<BOOKMARK:r2> VC R2($e82600):
bit 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 ┌──┬──┬───┬────┬───┬───┬───┬───┬────┬───┬───┬───┬───┬───┬───┬───┐ │YS│AH│VHT│EXON│H/P│B/P│G/G│G/T│BCON│SON│TON│GS4│GS3│GS2│GS1│GS0│ └──┴──┴───┴────┴───┴───┴───┴───┴────┴───┴───┴───┴───┴───┴───┴───┘
bit 15 YS Video cut (Do not display image even when superimposing) bit 14 AH Translucent: Text palette 0 ※Force translucent mode on regardless of EXON, H/P, etc. bit 13 VHT Translucent: Video image (used in Color Image Unit) bit 12 EXON Special priority/Translucent mode enabled bit 11 H/P %0 : Special priority selection %1 : Translucent mode selection bit 10 B/P %0 : Sharp reserved %1 : Enable special priority mode bit 9 G/G Translucent: Graphic screen bit 8 G/T Translucent: text/sprite screen ※Valid only when the priority of the graphics screen is high bit 7 BCON Border color display ON(%1)/OFF(%0) bit 6 SON Sprite screen ON(%1)/OFF(%0) bit 5 TON Text screen ON(%1)/OFF(%0) bit 4 GS4 Graphic screen ON(%1)/OFF(%0) (When the GVRAM size is 1024x1024) bit 3~0 GS3~GS0 Graphic screen ON(%1)/OFF(%0) (When the GVRAM size is 512x512)
※When the graphic screen is one page, all the same values are set for each bit of GS3~GS0. In the case of 2 pages, GS3~GS2/GS1~GS0 are treated as one set each and for each bit of the same set, set the same value to each.
x68000/vidcon_registers.txt · Last modified: 2019/08/27 20:45 by 127.0.0.1