Sprite Attribute 1 (with INC) Register: Difference between revisions

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core 2.00.23 changes
 
Core 2.00.26 changes
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Eight low bits of Y position. MSB of Y-pos is in "byte 5".
Eight low bits of Y position. MSB of Y-pos is in "byte 5".


After write into sprite-attribute "byte 2" ({{PortNo|$xx57}}), the {{NextRegNo|$34}} is incremented (with all consequences stemming from such action). If the sprite 63 was modified, the result of the increment is officially "undefined behaviour", and code should explicitly set valid 0..63 sprite index before next sprite-attribute manipulation.
After write into sprite-attribute "byte 2" ({{PortNo|$xx57}}), the {{NextRegNo|$34}} is incremented (with all consequences stemming from such action). If the sprite 127 was modified, the result of the increment is officially "undefined behaviour", and code should explicitly set valid 0..127 sprite index before next sprite-attribute manipulation.

Revision as of 09:09, 27 January 2019

Next Register Number $76
Readable No
Writable Yes
Short Description Same as NextReg:$36 (write second byte of sprite-attributes), plus increments NextReg:$34

Eight low bits of Y position. MSB of Y-pos is in "byte 5".

After write into sprite-attribute "byte 2" ( IO:$xx57), the NextReg:$34 is incremented (with all consequences stemming from such action). If the sprite 127 was modified, the result of the increment is officially "undefined behaviour", and code should explicitly set valid 0..127 sprite index before next sprite-attribute manipulation.