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⌂ ∞ Elite on the BBC Micro and NES

Drawing the screen: ADD_CYCLES

[NES version, Common]

       Name: ADD_CYCLES                                              [Show more]
       Type: Macro
   Category: Drawing the screen
    Summary: Add a specified number to the cycle count
  Deep dive: Drawing vector graphics using NES tiles

    Context: See this macro in context in the source code
 References: This macro is used as follows:
             * ClearBuffers uses ADD_CYCLES
             * ClearMemory uses ADD_CYCLES
             * ClearPlaneBuffers (Part 1 of 2) uses ADD_CYCLES
             * ClearPlaneBuffers (Part 2 of 2) uses ADD_CYCLES
             * ConsiderSendTiles uses ADD_CYCLES
             * SendBarPatts2ToPPU uses ADD_CYCLES
             * SendBarPattsToPPU uses ADD_CYCLES
             * SendNametableToPPU uses ADD_CYCLES
             * SendOtherBitplane uses ADD_CYCLES
             * SendPatternsToPPU (Part 1 of 6) uses ADD_CYCLES
             * SendPatternsToPPU (Part 3 of 6) uses ADD_CYCLES
             * SendPatternsToPPU (Part 5 of 6) uses ADD_CYCLES




 The following macro is used to add cycles to the cycle count:

   ADD_CYCLES cycles

 The cycle count is stored in the variable cycleCount. This macro assumes that
 the C flag is clear.



 Arguments:

   cycles               The number of cycles to add to the cycle count

   C flag               Must be clear for the addition to work



MACRO ADD_CYCLES cycles

 LDA cycleCount         ; Add cycles to cycleCount(1 0)
 ADC #LO(cycles)
 STA cycleCount
 LDA cycleCount+1
 ADC #HI(cycles)
 STA cycleCount+1

ENDMACRO