added some comments; new ft_flag bit #4: fd was opened by program

git-svn-id: svn://svn.cc65.org/cc65/trunk@1891 b7a2c559-68d2-44c3-8de9-860c34a00d81

diff --git a/libsrc/atari/fdtable.s b/libsrc/atari/fdtable.s
index 14b9ff17d4db88afee733c8b60a6a6faa8654efc..816ade8d399e431ef82f8bc50594174a6404db08 100644 (file)
--- a/libsrc/atari/fdtable.s
+++ b/libsrc/atari/fdtable.s
@@ -42,7 +42,7 @@
        cmp     fd_table+ft_iocb,x      ; entry in use?
        beq     inval                   ; no, return error
        lda     fd_table+ft_usa,x       ; get usage counter
-       beq     ok_notlast              ; 0?
+       beq     ok_notlast              ; 0? (shouldn't happen)
        sec
        sbc     #1                      ; decr usage counter
        sta     fd_table+ft_usa,x
@@ -53,10 +53,11 @@ retiocb:php
        tax
        plp
        bne     cont
-       php
        lda     #$ff
        sta     fd_table+ft_iocb,y      ; clear table entry
-       plp
+       lda     fd_table+ft_flag,y
+       and     #16                     ; opened by app?
+       eor     #16                     ; return set Z if yes
 cont:  rts
 
 ok_notlast:
@@ -251,7 +252,7 @@ do_open:lda tmp1
        ldy     #$ff
 srchfree:
        tya
-       cmp     fd_table,x
+       cmp     fd_table,x      ; check ft_iocb field for $ff
        beq     freefnd         ; found a free slot
        txa
        clc
@@ -289,7 +290,8 @@ l2: sta     fd_table+ft_dev,x       ; set device
        lda     loc_Y
        sta     fd_table+ft_iocb,x      ; set iocb index
        lda     loc_devnum
-       and     #7                      ; only 3 bits
+       and     #7                      ; device number is 3 bits
+       ora     #16                     ; indicated a fd actively opened by the app
        sta     fd_table+ft_flag,x
        lda     tmp2
        jsr     fdt_to_fdi              ; get new index