fix nmi scroll update

2022-04-06 20:21:03 +02:00 · 2022-04-06 20:21:03 +02:00 · ae0f787453
parent fe7b09d97b
commit ae0f787453
1 changed files with 3 additions and 4 deletions
--- a/asm/vector/nmi.asm
+++ b/asm/vector/nmi.asm
@ -199,10 +199,9 @@ NMI:
        LDX scroll_y
        STX PPU_SCROLL

-        LDX #$00        ; set bit 15 of t in PPU to 0
-        STX PPU_ADDR     ; (because, for unknown reason)
-        LDX #$00        ; to fix scrolling in the wrong nametable.
-        STX PPU_ADDR
+        ; set high order bit of X and Y
+        LDA ppu_ctrl_val
+        STA PPU_CTRL
    @scroll_end:

    @done: