fix cpeekc/cpeekcolor/cpeekrevers/cpeeks for atmos, replaces what is in #532

2025-05-24 20:03:44 +02:00
parent 228316ff58
commit 8d42c4a8c5
8 changed files with 134 additions and 31 deletions
--- a/libsrc/atmos/cpeeks.s
+++ b/libsrc/atmos/cpeeks.s
@@ -0,0 +1,54 @@
+;
+; 2017-06-20, Greg King
+;
+; void cpeeks (char* s, unsigned length);
+;
+
+        .export         _cpeeks
+
+        .import         setscrptr, popax
+        .importzp       ptr1, ptr2, ptr3, tmp1, tmp2
+
+        .macpack        generic
+
+
+_cpeeks:
+        eor     #<$FFFF         ; counting a word upward is faster
+        sta     ptr3            ; so, we use -(length + 1)
+        txa
+        eor     #>$FFFF
+        sta     ptr3+1
+
+        jsr     setscrptr       ; Set ptr2 and .Y to the cursor's address
+        sty     tmp2
+
+        jsr     popax
+        sta     tmp1            ; (will be a .Y index)
+        stx     ptr1+1
+        ldx     #<$0000
+        stx     ptr1
+        bze     L3              ; branch always
+
+L4:     ldy     tmp2
+        lda     (ptr2),y        ; Get char
+        iny
+        bnz     L2
+        inc     ptr2+1
+L2:     sty     tmp2
+        and     #<~$80          ; Remove reverse bit
+        ldy     tmp1
+        sta     (ptr1),y
+        iny
+        bnz     L1
+        inc     ptr1+1
+L1:     sty     tmp1
+
+L3:     inc     ptr3            ; count length
+        bnz     L4
+        inc     ptr3+1
+        bnz     L4
+
+        txa                     ; terminate the string
+        ldy     tmp1
+        sta     (ptr1),y
+        rts