fix cpeekc/cpeekcolor/cpeekrevers for atari 800

2025-05-24 18:34:44 +02:00
parent 0d5e365ee3
commit 6628c4ff43
5 changed files with 109 additions and 44 deletions
--- a/libsrc/atari/cpeekc.s
+++ b/libsrc/atari/cpeekc.s
@@ -0,0 +1,35 @@
+;
+; 2016-02-28, Groepaz
+; 2017-06-21, Greg King
+;
+; char cpeekc (void);
+;
+
+        .export         _cpeekc
+
+        .include        "atari.inc"
+
+
+_cpeekc:
+        lda     OLDCHR          ; get char under cursor
+        and     #<~$80          ; remove reverse bit
+
+        ;; convert internal screen code to AtSCII
+
+        tay
+        and     #%01100000
+        asl     a
+        asl     a
+        rol     a
+        rol     a
+        tax
+        tya
+        eor     intats,x
+        ldx     #>$0000
+        rts
+
+        .rodata
+intats: .byte   %00100000       ; -> %001xxxxx
+        .byte   %01100000       ; -> %010xxxxx
+        .byte   %01000000       ; -> %000xxxxx
+        .byte   %00000000       ; -> %011xxxxx