.MASKT ; Byte #2 Byte #1 Byte #0 Byte #0 Byte #1 Byte #2 ; 6543210 6543210 6543210 0123456 0123456 0123456 EQUD %000000000000000000000000 ; Black (00) in colour palette 0 ; 0000000 0000000 0000000 EQUD %010101010010101001010101 ; Violet (x0) in colour palette 0 ; x0x0x0x 0x0x0x0 x0x0x0x EQUD %001010100101010100101010 ; Green (0x) in colour palette 0 ; 0x0x0x0 x0x0x0x 0x0x0x0 EQUD %011111110111111101111111 ; White (xx) in colour palette 0 ; xxxxxxx xxxxxxx xxxxxxx EQUD %110101011010101011010101 ; Blue (x0) in colour palette 1 ; x0x0x0x 0x0x0x0 x0x0x0x EQUD %101010101101010110101010 ; Red (0x) in colour palette 1 ; 0x0x0x0 x0x0x0x 0x0x0x0 EQUD %101010101010101010101010 ; Fuzzy (red/black/blue) in colour palette 1 ; 0x0x0x0 0x0x0x0 0x0x0x0Name: MASKT [Show more] Type: Variable Category: Drawing lines Summary: High-resolution pixel bytes for drawing continuous lines of solid colourContext: See this variable in context in the source code References: This variable is used as follows: * CPIX uses MASKT * HLOIN uses MASKT
This table contains four bytes for each colour (the colour variables such as VIOLET and RED are indexes into this table). The first three bytes contain the values we need to store in screen memory to draw a continuous line in the relevant colour; the fourth byte is ignored and is zero. Bytes #0 and #1 contain the bit pattern for when the first byte is placed in an even-numbered pixel byte (counting along the pixel row), while bytes #1 and #2 contain the bit pattern for when the first byte is placed in an odd-numbered pixel byte. The comments show the on-off patterns that the high-resolution mode converts into colours, with bit 7 removed for clarity.