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BBC Micro Elite

Drawing lines: NLIN2 (Cassette version)

Name: NLIN2 [View in context] Type: Subroutine Category: Drawing lines Summary: Draw a screen-wide horizontal line at the pixel row in A
This draws a line from (2, A) to (254, A), which is almost screen-wide and fits in nicely between the white borders without clashing with it. Arguments: A The pixel row on which to draw the horizontal line
.NLIN2 STA Y1 \ Set (X1, Y1) = (2, A) LDX #2 STX X1 LDX #254 \ Set X2 = 254 STX X2 BNE HLOIN \ Call HLOIN to draw a horizontal line from (2, A) to \ (254, A) and return from the subroutine (this BNE is \ effectively a JMP as A will never be zero)