Working on the CBM file functions

git-svn-id: svn://svn.cc65.org/cc65/trunk@1533 b7a2c559-68d2-44c3-8de9-860c34a00d81
2002-11-17 22:45:55 +00:00
parent 43d5800702
commit 544ff5b900
11 changed files with 377 additions and 229 deletions
--- a/libsrc/cbm/rwcommon.s
+++ b/libsrc/cbm/rwcommon.s
@@ -0,0 +1,47 @@
+;
+; Ullrich von Bassewitz, 17.11.2002
+;
+; Common stuff for the read/write routines
+;
+
+        .export         rwcommon
+
+        .import         popax
+        .importzp       ptr1, ptr2, ptr3, tmp2
+
+        .include        "filedes.inc"
+
+
+;--------------------------------------------------------------------------
+; rwcommon: Pop the parameters from stack, preprocess them and place them
+; into zero page locations. Return carry set if the handle is invalid,
+; return carry clear if it is ok. If the carry is clear, the handle is
+; returned in A.
+
+.proc   rwcommon
+
+        jsr     popax           ; Get count
+        eor     #$FF
+        sta     ptr1
+        txa
+        eor     #$FF
+        sta     ptr1+1          ; Remember -count-1
+
+        jsr     popax           ; Get buf
+        sta     ptr2
+        stx     ptr2+1
+
+        lda     #$00
+        sta     ptr3
+        sta     ptr3+1          ; Clear ptr3
+
+        jsr     popax           ; Get the handle
+        sta     tmp2
+        cpx     #$01
+        bcs     inv
+        cmp     #MAX_FDS
+inv:    rts
+
+.endproc
+
+