Routines
Prev: 32174 Up: Map Next: 32275
32254: cxy2saddr
Screen address of top pixel row of character square at x,y.
Used by the routines at draw_alien_explosion, move_one_row_aliens_down, print_alien_row and print_udg.
Input
C xpos char
B ypos char
Output
DE Screen address
cxy2saddr 32254 LD D,B Early implementation of this function. asm_zx_cxy2saddr in z88dk is more efficient
32255 XOR A
32256 RR B
32258 RRA
32259 RR B
32261 RRA
32262 RR B
32264 RRA
32265 OR C
32266 LD E,A
32267 LD B,D
32268 LD A,24
32270 AND D
32271 OR 64
32273 LD D,A
32274 RET
Prev: 32174 Up: Map Next: 32275