Of course the routine could be written to be quicker (copy blocks opcodes or zero page ...)
The picture is displayed with a 65C816 cpu and a 65C816 routine, it loads from sdcard or from usb (from PC) if we want (it solves emulators issues, because program can be executed on the real hardware directly).
ca65 code :
Code: Select all
... sei .P816 .a8 .i16 clc xce rep #$10 ldx #$00 @L1: lda yessa,x sta $a000,x inx cpx #8000 bne @L1 sec xce cli rts ...