The horizontal beam position has a value of $0 to $E2. The least significant bit is not used in the comparison, so there are 113 positions available for Copper operations. This corresponds to 4 pixels in low resolution and 8 pixels in high resolution. Horizontal blanking falls in the range of $0F to $35. The standard screen (320 pixels wide) has an unused horizontal portion of $04 to $47 (during which only the background color is displayed). All lines are not the same length in NTSC. Every other line is a long line (228 color clocks , 0-$E3), with the others being 227 color clocks long. In PAL, they are all 227 long. The display sees all these lines as 227 1/2 color clocks long, while the Copper sees alternating long and short lines.
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