improved chk_supp: only do the test on SpartaDOS and only if the SDOS version

is below 4 (4 is SpartaDOS-X and supports seeking on all file systems)

git-svn-id: svn://svn.cc65.org/cc65/trunk@1362 b7a2c559-68d2-44c3-8de9-860c34a00d81

diff --git a/libsrc/atari/lseek.s b/libsrc/atari/lseek.s
index 259d89ab29bcde2e5011cd118c617d7eafaea35d..69e83da310f7992c03a5d65b49579696b176d309 100644 (file)
--- a/libsrc/atari/lseek.s
+++ b/libsrc/atari/lseek.s
@@ -10,7 +10,7 @@
        .export         _lseek
        .import         incsp6,__oserror
        .import         __inviocb,ldax0sp,ldaxysp,fdtoiocb
-       .import         __seterrno
+       .import         __seterrno,__dos_type
        .import         fd_table
        .importzp       sreg,ptr1,ptr2,ptr3,ptr4
        .importzp       tmp1,tmp2,tmp3
@@ -179,8 +179,9 @@ seek:       jsr     ldax0sp         ; get lower word of new offset
 ; tmp3:                iocb
 ; X:           index into fd_table
 ;
+; On non-SpartaDOS, seeking is not supported.
 ; We check, whether CIO function 39 (get file size) returns OK.
-; If yes, NOTE and POINT work with real file offset. @@@ check out more DOS versions @@@
+; If yes, NOTE and POINT work with real file offset.
 ; If not, NOTE and POINT work with the standard ScNum/Offset values.
 ; We remember a successful check in fd_table.ft_flag, bit 3.
 
@@ -190,8 +191,14 @@ chk_supp:
        bne     supp
 
 ; do the test
-unkn:  txa
+       lda     __dos_type
+       cmp     #SPARTADOS
+       bne     ns1
+       txa
        pha
+       lda     DOS+1           ; get SpartaDOS version
+       cmp     #$40
+       bcs     supp1           ; SD-X (ver 4.xx) supports seeking on all disks
        ldx     tmp3            ; iocb to use
        lda     #39             ; get file size
        sta     ICCOM,x
@@ -200,7 +207,7 @@ unkn:       txa
 
 ; seeking is supported on this DOS/Disk combination
 
-       pla
+supp1: pla
        tax
        lda     #8
        ora     fd_table+ft_flag,x
@@ -209,6 +216,6 @@ supp:       sec
        rts
 
 notsupp:pla
-       clc
+ns1:   clc
        rts