Routines
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9D30: Draw Beam
Used by the routine at UpdateBeams.
Records a beam in the table at BeamTable and draws it.
Input
B Number of bytes
C Pattern of each byte
HL Screen address of the first byte
IY Address of the entry in the table
DrawBeam 9D30 LD (IY+$00),L Record the low byte of the screen address.
9D33 LD (IY+$01),H Record the high byte of the screen address.
9D36 LD (IY+$02),B Record the number of bytes.
9D39 LD (IY+$03),C Record the pattern.
DrawBeam_Loop 9D3C LD A,C Fetch the pattern.
9D3D OR (HL) Set the pixels.
9D3E LD (HL),A
9D3F INC L Move on to the next byte of the row.
9D40 DJNZ DrawBeam_Loop Loop back to DrawBeam_Loop for each byte.
9D42 RET Return.
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