The spans do now contain the size of a span, no longer the end offset.

[cc65] / libsrc / atari / diopncls.s

diff --git a/libsrc/atari/diopncls.s b/libsrc/atari/diopncls.s
index 7826e0cc19a1c4faa5fea3c7fcdd3d39c8a8f7bc..09398b9acf6f8c2a496d4e0b8c1779dceb41f0ab 100644 (file)
--- a/libsrc/atari/diopncls.s
+++ b/libsrc/atari/diopncls.s
@@ -1,20 +1,22 @@
 ;
-; Christian Groessler, October 2000
+; Christian Groessler, February 2005
 ;
-; This file provides the __dio_open and __dio_close functions
+; This file provides the _dio_open and _dio_close functions
 ; Since on the Atari no real open and close is necessary, they
-; do not much. The __dio_open sets the sector size of the
-; drive which is later used by the _dio_read and _dio_write
-; functions.
+; do not open or close something. The _dio_open sets the sector
+; size of the drive which is later used by the _dio_read and
+; _dio_write functions. To query the sector size, the _dio_open
+; accesses the disk drive.
 ;
-; dhandle_t     __fastcall__ dio_open  (driveid_t drive_id);
+; dhandle_t    __fastcall__ dio_open  (driveid_t drive_id);
 ; unsigned char __fastcall__ dio_close (dhandle_t handle);
 ;
 
-       .export         _dio_open,_dio_close
+       .export         _dio_open, _dio_close
        .export         sectsizetab
-       .import         __oserror
-       .importzp       ptr1,tmp1
+       .import         __oserror, __sio_call, _dio_read
+       .import         pushax, addysp, subysp
+       .importzp       ptr2, sp
        .include        "atari.inc"
 
 
@@ -25,8 +27,16 @@ sectsizetab:
 
 .code
 
+; code for _dio_open
 
-.proc  _dio_open
+_inv_drive:
+       lda     #NONDEV         ; non-existent device
+       sta     __oserror
+       lda     #0
+       tax
+       rts                     ; return NULL
+
+_dio_open:
 
        cmp     #NUMDRVS        ; valid drive id?
        bcs     _inv_drive
@@ -34,7 +44,7 @@ sectsizetab:
        asl     a               ; make index from drive id
        asl     a
        tax
-       lda     #128            ; currently hardcoded (until I get an 815 :-)
+       lda     #128                            ; preset sectsize
        sta     sectsizetab+sst_sectsize,x
        sta     sectsizetab+sst_flag,x          ; set flag that drive is "open"
        lda     #0
@@ -42,38 +52,112 @@ sectsizetab:
        sta     __oserror                       ; success
        tya
        sta     sectsizetab+sst_driveno,x
-;      lda     #SSTIDVAL
-;      sta     sectsizetab+sst_id+1,x
-       stx     tmp1
+       stx     ptr2
        lda     #<sectsizetab
        clc
-       adc     tmp1
-       sta     tmp1
+       adc     ptr2
+       sta     ptr2
        lda     #>sectsizetab
        adc     #0
        tax
-       lda     tmp1
-       rts
+       stx     ptr2+1          ; ptr2: pointer to sectsizetab entry
 
-_inv_drive:
-       lda     #NONDEV         ; non-existent device
-       sta     __oserror
-       lda     #0
+; query drive for current sector size
+; procedure:
+;   - read sector #4 (SIO command $54) to update drive status;
+;     read length is 128 bytes, buffer is allocated on the stack,
+;         sector data is ignored;
+;     returned command status is ignored, we will get an error with
+;         a DD disk anyway (read size 128 vs. sector size 256);
+;   - issue SIO command $53 (get status) to retrieve the sector size;
+;     use the DVSTAT system area as return buffer;
+;     if the command returns with an error, set sector size to 128
+;         bytes;
+;
+
+       ldy     #128
+       jsr     subysp          ; allocate buffer on the stack
+
+       lda     sp
+       pha
+       lda     sp+1
+       pha                     ; save sp (buffer address) on processor stack
+
+       lda     ptr2
+       ldx     ptr2+1
+       jsr     pushax          ; handle
+
+       ldx     #0
+       lda     #4
+       jsr     pushax          ; sect_num
+
+       pla
        tax
-       rts                     ; return NULL
+       pla                     ; AX - buffer address
+
+                               ; sst_sectsize currently 128
+       jsr     _dio_read       ; read sector to update status
+
+       ldy     #128
+       jsr     addysp          ; discard stack buffer
+
+       lda     ptr2
+       ldx     ptr2+1
+       jsr     pushax          ; handle
+
+       ldx     #0
+       lda     #4
+       jsr     pushax          ; dummy sector #, ignored by this SIO command,
+                               ; but set to circumvent the special 1-3 sector
+                               ; handling in __sio_call
+
+       ldx     #>DVSTAT
+       lda     #<DVSTAT
+       jsr     pushax          ; buffer address
+
+       ldy     #sst_sectsize
+       lda     #4
+       sta     (ptr2),y        ; 4 bytes transfer
+
+       ldx     #%01000000      ; direction value
+       lda     #SIO_STAT       ; get status
+
+       jsr     __sio_call
+
+       bmi     error
+
+       ldy     #sst_sectsize
+       lda     DVSTAT
+       and     #%100000
+       beq     s128
+
+;s256
+       lda     #0
+       sta     (ptr2),y
+       iny
+       lda     #1
+
+finish:        sta     (ptr2),y        ; set default sector size       
+fini2: lda     ptr2
+       ldx     ptr2+1
+       rts
+
+error: ldy     #sst_sectsize
+s128:  lda     #128
+       bne     finish
+
+; end of _dio_open
 
-.endproc
 
 .proc  _dio_close
 
-       sta     ptr1
-       stx     ptr1+1
+       sta     ptr2
+       stx     ptr2+1
        lda     #0
        ldy     #sst_flag
-       sta     (ptr1),y
+       sta     (ptr2),y
        sta     __oserror       ; success
        tax
        rts                     ; return no error
 
 .endproc
-