Semantic search
Number | Readable | Writable | Description | |
---|---|---|---|---|
ULA Y Offset Register | $27 | true | true | Pixel Y offset (0..191) to use when drawing ULA Layer. |
Keymap High Address Register | $28 | true | true | PS/2 Keymap address MSB, read (pending) first byte of palette colour |
Keymap Low Address Register | $29 | false | true | PS/2 Keymap address LSB. |
Keymap High Data Register | $2A | false | true | High data to PS/2 Keymap (MSB of data in bit 0) |
Keymap Low Data Register | $2B | false | true | Low eight LSBs of PS/2 Keymap data. |
DAC B (left) mirror Register | $2C | true | true | DAC B mirror, read current I2S left MSB |
DAC A+D (mono) mirror Register | $2D | true | true | SpecDrum port 0xDF / DAC A+D mirror, read current I2S LSB |
DAC C (right) mirror Register | $2E | true | true | DAC C mirror, read current I2S right MSB |
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 X LSB Register | $30 | true | true | Sets the pixel offset (eight low 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. |
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. |
Sprite port-mirror Index Register | $34 | true | true | Selects sprite index 0..127 to be affected by writes to other Sprite ports (and mirrors). |
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 Register | $36 | false | true | Nextreg port-mirror to write directly into "byte 2" of Sprite Attribute Upload ($xx57 / 87). |
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 Register | $38 | false | true | Nextreg port-mirror to write directly into "byte 4" of Sprite Attribute Upload ($xx57 / 87). |
Sprite port-mirror Attribute 4 Register | $39 | false | true | Nextreg port-mirror to write directly into "byte 5" of Sprite Attribute Upload ($xx57 / 87). |
Palette Index Register | $40 | true | true | Chooses an palette element (index) to manipulate with |