Expansion Bus Control Register | $81 | true | true | Expansion bus controls |
Expansion Bus Decoding b0-7 Register | $86 | true | true | When expansion bus is enabled: Internal ports decoding mask |
Expansion Bus Decoding b16-23 Register | $88 | true | true | When expansion bus is enabled: Internal ports decoding mask |
Expansion Bus Decoding b24-31 Register | $89 | true | true | When expansion bus is enabled: Internal ports decoding mask |
Expansion Bus Decoding b8-15 Register | $87 | true | true | When expansion bus is enabled: Internal ports decoding mask |
Expansion Bus Enable Register | $80 | true | true | Expansion bus enable/config |
Expansion Bus I/O Propagate Register | $8A | true | true | Monitoring internal I/O or adding external keyboard |
Extended Keys 0 Register | $B0 | true | false | Read Next keyboard compound keys separately |
Extended Keys 1 Register | $B1 | true | false | Read Next keyboard compound keys separately |
Global Transparency Register | $14 | true | true | Sets the "transparent" colour for Layer 2, ULA and LoRes pixel data. |
Internal Port Decoding b0-7 Register | $82 | true | true | Enabling internal ports decoding |
Internal Port Decoding b16-23 Register | $84 | true | true | Enabling internal ports decoding |
Internal Port Decoding b24-31 Register | $85 | true | true | Enabling internal ports decoding |
Internal Port Decoding b8-15 Register | $83 | true | true | Enabling internal ports decoding |
Keymap High Address Register | $28 | true | true | PS/2 Keymap address MSB, read (pending) first byte of palette colour |
Keymap High Data Register | $2A | false | true | High data to PS/2 Keymap (MSB of data in bit 0) |
Keymap Low Address Register | $29 | false | true | PS/2 Keymap address LSB. |
Keymap Low Data Register | $2B | false | true | Low eight LSBs of PS/2 Keymap data. |
Layer 2 Control Register | $70 | true | true | Layer 2 resolution, palette offset |
Layer 2 RAM Page Register | $12 | true | true | Sets the bank number where Layer 2 video memory begins. |
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. |