1,885
edits
Changes
→Bitmap Code
2. The following code fills the emulator's bitmapped display with the colour yellow. Paste this code into the emulator:
lda #$00 ; set a pointer at in memory location $40 to point to $0200 sta $40 ; ... low byte ($00) goes in address $40 lda #$02 sta $41 ; ... high byte ($02) goes into address $41
lda #$07 ; colour number
ldy #$00 ; set index to 0
loop: sta ($40),y ; set pixel colour at the address (pointer)+Y
iny ; increment index
bne loop ; continue until done the page(256 pixels)
inc $41 ; increment the page
3. Test the code by pressing the Assemble button, then the Run button. If the there are any errors assembling (compiling) the code, they will appear in the message area at the bottom of the page. Make sure the code is running correctly and that you understands how it works.
=== Calculating Performance ===