The 6800 code has been updated using a similar optimization as with the 6803 version. Even though the 6800 doesn't support the 16 bit accumulator, the change still cuts the number of index register swaps in half, and the code that writes to the screen is now faster than the 6502 version by 28 clock cycles. If the 6800 address calculation code can be optimized a little, the 6800 may actually beat the 6502 at this. Some self modifying code and a couple tables may be required but it may be possible. The scroll may be slightly faster as well.
To be fair, this screen layout works well for the 680X processors and a standard bitmap may be a little slower. If I were to create a custom graphics chip for the 680X series, I'd include at least one screen layout like the Plus/4's simply because it works so well here.
To be fair, this screen layout works well for the 680X processors and a standard bitmap may be a little slower. If I were to create a custom graphics chip for the 680X series, I'd include at least one screen layout like the Plus/4's simply because it works so well here.
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