Layer 2 RAM Shadow Page Register | $13 | true | true | Sets the bank number where the Layer 2 shadow screen begins. |
Layer 2 X Offset MSB Register | $71 | true | true | Sets the pixel offset used for drawing Layer 2 graphics on the screen. |
Layer 2 X Offset Register | $16 | true | true | Sets the pixel offset used for drawing Layer 2 graphics on the screen. |
Layer 2 Y Offset Register | $17 | true | true | Sets the Y offset used when drawing Layer 2 graphics on the screen. |
LoRes Control Register | $6A | true | true | LoRes Radastan mode |
LoRes X Offset Register | $32 | true | true | Pixel X offset (0..255) to use when drawing LoRes Layer. |
LoRes Y Offset Register | $33 | true | true | Pixel Y offset (0..191) to use when drawing LoRes Layer. |
Machine ID Register | $00 | true | false | Identifies TBBlue board type. Should always be 10 on Next. |
Machine Type Register | $03 | true | true | Identifies timing and machine type. |
Memory Mapping Register | $8E | true | true | Control classic Spectrum memory mapping |
Memory management slot 0 bank | $50 | true | true | Selects the 8k-bank stored in 8k-slot 0 (see Memory map). |
Memory management slot 1 bank | $51 | true | true | Selects the 8k-bank stored in 8k-slot 1 (see Memory map). |
Memory management slot 2 bank | $52 | true | true | Selects the 8k-bank stored in 8k-slot 2 (see Memory map). |
Memory management slot 3 bank | $53 | true | true | Selects the 8k-bank stored in 8k-slot 3 (see Memory map). |
Memory management slot 4 bank | $54 | true | true | Selects the 8k-bank stored in 8k-slot 4 (see Memory map). |
Memory management slot 5 bank | $55 | true | true | Selects the 8k-bank stored in 8k-slot 5 (see Memory map). |
Memory management slot 6 bank | $56 | true | true | Selects the 8k-bank stored in 8k-slot 6 (see Memory map). |
Memory management slot 7 bank | $57 | true | true | Selects the 8k-bank stored in 8k-slot 7 (see Memory map). |
Next Reset Register | $02 | true | true | Identifies type of last reset. Can be written to force reset. |
Palette Index Register | $40 | true | true | Chooses an palette element (index) to manipulate with |
Palette Value Register | $41 | true | true | Use to set/read 8-bit colours of the ULANext palette. |
Peripheral 1 Register | $05 | true | true | Sets joystick mode, video frequency and Scandoubler. |
Peripheral 2 Register | $06 | true | true | Enables CPU Speed key, DivMMC, Multiface, Mouse and AY audio. |
Peripheral 3 Register | $08 | true | true | ABC/ACB Stereo, Internal Speaker, SpecDrum, Timex Video Modes, Turbo Sound Next, RAM contention and [un]lock 128k paging. |
Peripheral 4 Register | $09 | true | true | Sets scanlines, AY mono output, Sprite-id lockstep, reset DivMMC mapram and disable HDMI audio. |
Peripheral 5 Register | $0A | true | true | Mouse buttons and DPI config |
Pi GPIO Output Enable Register | $90-$93 | true | true | Enables GPIO pins output |
Pi GPIO Register | $98-$9B | true | true | GPIO pins mapped to Next Register |
Pi I2S Audio Control Register | $A2 | true | true | Pi I2S controls |
Pi I2S Clock Divide Register | $A3 | true | true | Pi I2S clock divide in master mode. |
Pi Peripheral Enable Register | $A0 | true | true | Enable Pi peripherals: UART, Pi hats, I2C, SPI |
Sprite and Layers System Register | $15 | true | true | Enables/disables Sprites and Lores Layer, and chooses priority of sprites and Layer 2. |
Sprite port-mirror Attribute 0 (with INC) Register | $75 | false | true | Same as Sprite port-mirror Attribute 0 Register ($35) (write first byte of sprite-attributes), plus increments Sprite port-mirror Index Register ($34) |
Sprite port-mirror Attribute 0 Register | $35 | false | true | Nextreg port-mirror to write directly into "byte 1" of Sprite Attribute Upload ($xx57 / 87). |
Sprite port-mirror Attribute 1 (with INC) Register | $76 | false | true | Same as Sprite port-mirror Attribute 1 Register ($36) (write second byte of sprite-attributes), plus increments Sprite port-mirror Index Register ($34) |
Sprite port-mirror Attribute 1 Register | $36 | false | true | Nextreg port-mirror to write directly into "byte 2" of Sprite Attribute Upload ($xx57 / 87). |
Sprite port-mirror Attribute 2 (with INC) Register | $77 | false | true | Same as Sprite port-mirror Attribute 2 Register ($37) (write third byte of sprite-attributes), plus increments Sprite port-mirror Index Register ($34) |
Sprite port-mirror Attribute 2 Register | $37 | false | true | Nextreg port-mirror to write directly into "byte 3" of Sprite Attribute Upload ($xx57 / 87). |
Sprite port-mirror Attribute 3 (with INC) Register | $78 | false | true | Same as Sprite port-mirror Attribute 3 Register ($38) (write fourth byte of sprite-attributes), plus increments Sprite port-mirror Index Register ($34) |
Sprite port-mirror Attribute 3 Register | $38 | false | true | Nextreg port-mirror to write directly into "byte 4" of Sprite Attribute Upload ($xx57 / 87). |
Sprite port-mirror Attribute 4 (with INC) Register | $79 | false | true | The same as Sprite port-mirror Attribute 4 Register ($39) (write fifth byte of sprite-attributes), plus increments Sprite port-mirror Index Register ($34) |
Sprite port-mirror Attribute 4 Register | $39 | false | true | Nextreg port-mirror to write directly into "byte 5" of Sprite Attribute Upload ($xx57 / 87). |
Sprite port-mirror Index Register | $34 | true | true | Selects sprite index 0..127 to be affected by writes to other Sprite ports (and mirrors). |
Sprites Transparency Index Register | $4B | true | true | Index into sprite palette (of "transparent" colour). |
Tile Definitions Base Address Register | $6F | true | true | Base address of the tiles' graphics. |
Tilemap Base Address Register | $6E | true | true | Base address of the 40x32 or 80x32 tile map (similar to text-mode of other computers). |
Tilemap Control Register | $6B | true | true | Controls Tilemap mode. |
Tilemap Offset X LSB Register | $30 | true | true | Sets the pixel offset (eight low bits) used for drawing Tilemap graphics on the screen. |
Tilemap Offset X MSB Register | $2F | true | true | Sets the pixel offset (two high bits) used for drawing Tilemap graphics on the screen. |
Tilemap Offset Y Register | $31 | true | true | Sets the pixel offset used for drawing Tilemap graphics on the screen. |