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2018-03-08 22:10:11 +01:00
parent a32c50a6bc
commit 970c5f6184
1 changed files with 3 additions and 0 deletions
--- a/libsrc/runtime/ldec.s
+++ b/libsrc/runtime/ldec.s
@@ -13,12 +13,15 @@ deceaxy:
        sec
        sbc     tmp1
        bcs     @L9
+; borrow from X
        dex
        cpx     #$ff
        bne     @L9
+; X wrapped from zero to $ff, borrow from sreg
        dec     sreg
        cpx     sreg
        bne     @L9
+; sreg wrapped from zero to $ff, borrow from sreg+1
        dec     sreg+1
@L9:    rts