.TWOS3 ; Byte #1 Byte #0 Byte #0 Byte #1 ; 6543210 6543210 0123456 0123456 EQUW %0000000000000011 ; xx00000 0000000 EQUW %0000000000000110 ; 0xx0000 0000000 EQUW %0000000000001100 ; 00xx000 0000000 EQUW %0000000000011000 ; 000xx00 0000000 EQUW %0000000000110000 ; 0000xx0 0000000 EQUW %0000000001100000 ; 00000xx 0000000 EQUW %0000000101000000 ; 000000x x000000 EQUW %0000000000000111 ; xxx0000 0000000 EQUW %0000000000001110 ; 0xxx000 0000000 EQUW %0000000000011100 ; 00xxx00 0000000 EQUW %0000000000111000 ; 000xxx0 0000000 EQUW %0000000001110000 ; 0000xxx 0000000 EQUW %0000000101100000 ; 00000xx x000000 EQUW %0000001101000000 ; 000000x xx00000Name: TWOS3 [Show more] Type: Variable Category: Drawing pixels Summary: Ready-made two-pixel and three-pixel bytes in white, with an extra byte to cater for overflow into the next pixel byteContext: See this variable in context in the source code References: This variable is used as follows: * PIXEL uses TWOS3
This table contains ready-made pixel bytes for drawing a white two-pixel or three-pixel dash in the high-resolution screen mode on the Apple II. The first half of the table contains two-pixel dashes, with the entry at TWOS3+X containing a two-pixel dash starting at pixel X within the first pixel byte. The second half of the table contains three-pixel dashes, with the entry at TWOS3+14+X containing a three-pixel dash starting at pixel X within the first pixel byte. Bit 7 in each byte is used to define the colour palette in that byte, so the pixels themselves are defined in bits 0 to 6. The pixels in bits 0 to 6 appear in that order on-screen, so bit 0 is on the left. The comments below show how the two bytes map into the screen, with seven pixels per byte.