cbm stuff from greggs pull request

2017-12-11 19:49:14 +01:00
parent 947b09ad96
commit 8902730756
21 changed files with 936 additions and 7 deletions
--- a/libsrc/cbm610/cpeekrevers.s
+++ b/libsrc/cbm610/cpeekrevers.s
@@ -0,0 +1,29 @@
+;
+; 2016-02-28, Groepaz
+; 2017-06-19, Greg King
+;
+; unsigned char cpeekrevers (void);
+;
+
+        .export         _cpeekrevers
+
+        .import         plot
+        .import         CURS_X: zp, CharPtr: zp
+
+        .include        "cbm610.inc"
+
+
+_cpeekrevers:
+        ldx     IndReg
+        ldy     #$0F
+        sty     IndReg
+
+        ldy     CURS_X
+        lda     (CharPtr),y     ; get char from system bank
+        stx     IndReg
+        ldx     #>$0000
+        and     #$80            ; get reverse bit
+        asl     a
+        tax                     ; ldx #>$0000
+        rol     a               ; return boolean value
+        rts