VDP register reference

$80xx: mode set register #1
$81xx: mode set register #2
$82xx: plane A table address
$83xx: window table address
$84xx: plane B table address
$85xx: sprite table address
$87xx: background color
$8Axx: hblank interrupt rate
$8Bxx: mode set register #3
$8Cxx: mode set register #4
$8Dxx: hscroll table address
$8Fxx: autoincrement
$90xx: tilemap size
$91xx: window X division
$92xx: window Y division
$93xx,$94xx: DMA length
$95xx,$96xx,$97xx: DMA source

`$80xx`: mode set register #1

VDP register `$80xx`: mode set register #1
Bit 7	Bit 6	Bit 5	Bit 4	Bit 3	Bit 2	Bit 1	Bit 0
`0`	`0`	`LCB`	`IE1`	`0`	`1`	`M3`	`0`

LCB: 1 to blank the leftmost column (8px wide)
IE1: 1 to enable hblank interrupt
M3: 1 to freeze HV counter

`$81xx`: mode set register #2

VDP register `$81xx`: mode set register #2
Bit 7	Bit 6	Bit 5	Bit 4	Bit 3	Bit 2	Bit 1	Bit 0
`0`	`DISP`	`IE0`	`M1`	`M2`	`1`	`0`	`0`

DISP: 1 to enable rendering
IE0: 1 to enable vblank interrupt
M1: 1 to allow DMA operations
M2: vertical resolution in tiles
- 0: 28 tiles (V28 mode)
- 1: 30 tiles (V30 mode)

Note that V30 mode only works properly on PAL systems.

`$82xx`: plane A table address

VDP register `$82xx`: plane A table address
Bit 7	Bit 6	Bit 5	Bit 4	Bit 3	Bit 2	Bit 1	Bit 0
`0`	`0`	`SA15`	`SA14`	`SA13`	`0`	`0`	`0`

SA15-13: plane A table base address (divided by $2000)

`$83xx`: window table address

VDP register `$83xx`: window table address
Bit 7	Bit 6	Bit 5	Bit 4	Bit 3	Bit 2	Bit 1	Bit 0
`0`	`0`	`WD15`	`WD14`	`WD13`	`WD12`	`WD11`	`0`

WD15-11: window table base address (divided by $800). In H40 mode, WD11 must be 0.

`$84xx`: plane B table address

VDP register `$84xx`: plane B table address
Bit 7	Bit 6	Bit 5	Bit 4	Bit 3	Bit 2	Bit 1	Bit 0
`0`	`0`	`0`	`0`	`0`	`SB15`	`SB14`	`SB13`

SB15-13: plane B table base address (divided by $2000)

`$85xx`: sprite table address

VDP register `$85xx`: sprite table address
Bit 7	Bit 6	Bit 5	Bit 4	Bit 3	Bit 2	Bit 1	Bit 0
`0`	`AT15`	`AT14`	`AT13`	`AT12`	`AT11`	`AT10`	`AT9`

AT15-9: sprite table base address (divided by $200). In H40 mode, AT9 must be 0.

`$87xx`: background color

VDP register `$87xx`: background color
Bit 7	Bit 6	Bit 5	Bit 4	Bit 3	Bit 2	Bit 1	Bit 0
`0`	`0`	`CPT1`	`CPT0`	`COL3`	`COL2`	`COL1`	`COL0`

CPT1-0: background color palette
COL3-0: background color index

`$8Axx`: hblank interrupt rate

VDP register `$8Axx`: hblank interrupt rate
Bit 7	Bit 6	Bit 5	Bit 4	Bit 3	Bit 2	Bit 1	Bit 0
`HIT7`	`HIT6`	`HIT5`	`HIT4`	`HIT3`	`HIT2`	`HIT1`	`HIT0`

HIT7-0: how many lines to wait between hblank interrupts

`$8Bxx`: mode set register #3

VDP register `$8Bxx`: mode set register #3
Bit 7	Bit 6	Bit 5	Bit 4	Bit 3	Bit 2	Bit 1	Bit 0
`0`	`0`	`0`	`0`	`IE2`	`VSCR`	`HSCR`	`LSCR`

IE2: 1 to enable external interrupt
VSCR: vertical scroll mode
- 0: full scroll
- 1: scroll every two tiles
H/LSCR: horizontal scroll mode
- 00: full scroll
- 01: scroll eight lines, then repeat
- 10: scroll every tile
- 11: scroll every line

`$8Cxx`: mode set register #4

VDP register `$8Cxx`: mode set register #4
Bit 7	Bit 6	Bit 5	Bit 4	Bit 3	Bit 2	Bit 1	Bit 0
`RS0`	`0`	`0`	`0`	`S/TE`	`LSM1`	`LSM0`	`RS1`

RS0-1: horizontal resolution in tiles
- 00: 32 tiles (H32 mode)
- 11: 40 tiles (H40 mode)
S/TE: 1 to enable shadow/highlight
LSM1-0: interlaced mode
- 00: no interlacing
- 01: mode 1 (interlaced but no resolution increase)
- 11: mode 2 (interlaced with higher resolution)

`$8Dxx`: hscroll table address

VDP register `$8Dxx`: hscroll table address
Bit 7	Bit 6	Bit 5	Bit 4	Bit 3	Bit 2	Bit 1	Bit 0
`0`	`0`	`HS15`	`HS14`	`HS13`	`HS12`	`HS11`	`HS10`

HS15-10: hscroll table base address (divided by $400)

`$8Fxx`: autoincrement

VDP register `$8Fxx`: autoincrement
Bit 7	Bit 6	Bit 5	Bit 4	Bit 3	Bit 2	Bit 1	Bit 0
`INC7`	`INC6`	`INC5`	`INC4`	`INC3`	`INC2`	`INC1`	`INC0`

INC7-0: autoincrement amount (in bytes)

`$90xx`: tilemap size

VDP register `$90xx`: tilemap size
Bit 7	Bit 6	Bit 5	Bit 4	Bit 3	Bit 2	Bit 1	Bit 0
`0`	`0`	`VSZ1`	`VSZ0`	`0`	`0`	`HSZ1`	`HSZ0`

VSZ1-0: vertical size (see below)
HSZ1-0: horizontal size (see below)

Possible tilemap sizes
`VSZ1-0`	`HSZ1-0`	Size in tiles
`00`	`00`	32×32
`00`	`01`	64×32
`00`	`11`	128×32
`01`	`00`	32×64
`01`	`01`	64×64
`11`	`00`	32×128

Other tilemap sizes will not work as expected.

`$91xx`: window X division

VDP register `$91xx`: window X division
Bit 7	Bit 6	Bit 5	Bit 4	Bit 3	Bit 2	Bit 1	Bit 0
`RIGT`	`0`	`0`	`WHP5`	`WHP4`	`WHP3`	`WHP2`	`WHP1`

RIGT: where to display window
- 0: to the left of the split X coordinate
- 1: to the right of the split X coordinate
WHP5-1: X coordinate of split (in 16px steps)

`$92xx`: window Y division

VDP register `$92xx`: window Y division
Bit 7	Bit 6	Bit 5	Bit 4	Bit 3	Bit 2	Bit 1	Bit 0
`DOWN`	`0`	`0`	`WVP4`	`WVP3`	`WVP2`	`WVP1`	`WVP0`

DOWN: where to display window
- 0: above the split Y coordinate
- 1: below the split Y coordinate
WVP4-0: Y coordinate of split (in 8px steps)

`$93xx`,`$94xx`: DMA length

VDP register `$93xx`: DMA length (low)
Bit 7	Bit 6	Bit 5	Bit 4	Bit 3	Bit 2	Bit 1	Bit 0
`LG7`	`LG6`	`LG5`	`LG4`	`LG3`	`LG2`	`LG1`	`LG0`

VDP register `$94xx`: DMA length (high)
Bit 7	Bit 6	Bit 5	Bit 4	Bit 3	Bit 2	Bit 1	Bit 0
`LG15`	`LG14`	`LG13`	`LG12`	`LG11`	`LG10`	`LG9`	`LG8`

LG15-0: DMA length

`$95xx`,`$96xx`,`$97xx`: DMA source

VDP register `$95xx`: DMA source address (low)
Bit 7	Bit 6	Bit 5	Bit 4	Bit 3	Bit 2	Bit 1	Bit 0
`SA8`	`SA7`	`SA6`	`SA5`	`SA4`	`SA3`	`SA2`	`SA1`

VDP register `$96xx`: DMA source address (middle)
Bit 7	Bit 6	Bit 5	Bit 4	Bit 3	Bit 2	Bit 1	Bit 0
`SA16`	`SA15`	`SA14`	`SA13`	`SA12`	`SA11`	`SA10`	`SA9`

VDP register `$97xx`: DMA source address (high)
Bit 7	Bit 6	Bit 5	Bit 4	Bit 3	Bit 2	Bit 1	Bit 0
`DMD1`	`DMD0`	`SA22`	`SA21`	`SA20`	`SA19`	`SA18`	`SA17`

SA22-1: DMA source
DMD1-0: DMA operation type
- 0*: DMA transfer (DMD0 becomes SA23)
- 10: VRAM fill
- 11: VRAM copy

$80xx: mode set register #1

$81xx: mode set register #2

$82xx: plane A table address

$83xx: window table address

$84xx: plane B table address

$85xx: sprite table address

$87xx: background color

$8Axx: hblank interrupt rate

$8Bxx: mode set register #3

$8Cxx: mode set register #4

$8Dxx: hscroll table address

$8Fxx: autoincrement

$90xx: tilemap size

$91xx: window X division

$92xx: window Y division

$93xx,$94xx: DMA length

$95xx,$96xx,$97xx: DMA source

`$80xx`: mode set register #1

`$81xx`: mode set register #2

`$82xx`: plane A table address

`$83xx`: window table address

`$84xx`: plane B table address

`$85xx`: sprite table address

`$87xx`: background color

`$8Axx`: hblank interrupt rate

`$8Bxx`: mode set register #3

`$8Cxx`: mode set register #4

`$8Dxx`: hscroll table address

`$8Fxx`: autoincrement

`$90xx`: tilemap size

`$91xx`: window X division

`$92xx`: window Y division

`$93xx`,`$94xx`: DMA length

`$95xx`,`$96xx`,`$97xx`: DMA source