LoRes X Offset Register

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Revision as of 14:23, 11 November 2019 by Ped7g (talk | contribs) (Ped7g moved page ULA / LoRes Layer X Offset Register to LoRes X Offset Register: core 3.0 change)
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Number $32
Readable Yes
Writable Yes
Short Description Pixel offset to use when drawing ULA or LoRes Layer.

bits 7-0 = X Offset (0-255) (Reset to 0 after a reset)

ULA screen at this moment scrolls horizontally only by whole "characters" (by multiples of 8 pixels), the low 3 bits of offset value are ignored (as of core 2.00.26, may get modified/updated in later cores to scroll per single pixel also horizontally).

LoRes scrolls in "half-pixels" at the same resolution and smoothness as Layer 2.

NEW in core 3.0:

This is now LoRes only offset, ULA will have it's own registers $26 and $27 (to be added to wiki) (also it's not 100% clear to me if this split did happen already in the version delivered to factory, or it will happen in the following bugfix update, but it should eventually happen). (I will update + cleanup this over time as I will be able to verify all the info)