SuperHires mode has a finer granularity of sprite positioning than either Hires or Lores modes. This allows for positioning the sprite every other SuperHires pixel on 70ns boundaries. The ECS registers SPRxPOS and SPRxCTL work together as position, size and sprite feature control registers. They are usually loaded by the sprite DMA channel, during horizontal blank, however they may be loaded by the processor. The two registers are defined as follows: SPRxPOS W A D Sprite x vertical-horiz start position data Bit Use ---- ---- 15-08 07-00 SH8-SH1 Start horizontal value. Low bit (SH0) in SPRxCTL. SPRxCTL W A D Sprite x position and control data Bit Use ---- ---- 15-08 07 06 05 04 SHSH1 Start horizontal (SHR mode) 70ns increment 03 SHSH0 Start horizontal (SHR mode) 35ns (unimplemented) 02 01 00 SH0 Start horiz. value Low bit 140 ns increment Note: bits 3 and 4 are in the ECS chips only. Warning: -------- 70ns sprite positions are only available in SuperHires mode. Attempting to use 70ns sprite positioning with Hires mode under the current system may lead to unpredictable results.
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