define sysRandom $fe

Snow:
lda sysRandom  ;get a random number
and #$01       ;remove all but bit 0
sta $0200,x    ;store in first section of VRAM

lda sysRandom  ;get a random number
and #$01       ;remove all but bit 0
sta $0300,x    ;store in second section of VRAM

lda sysRandom  ;get a random number
and #$01       ;remove all but bit 0
sta $0400,x    ;store in third section of VRAM

lda sysRandom  ;get a random number
and #$01       ;remove all but bit 0
sta $0500,x    ;store in last section of VRAM

inx            ;next X
jmp Snow       ;loop forever