I wasn't aware that the unit numbers in the ProDOS device list contain device type identifiers in the low nibble. So if we can't use the device list entries as-is we can as well present the high nibble as low nibble to the user thus providing more meaningful device numbers.

git-svn-id: svn://svn.cc65.org/cc65/trunk@5852 b7a2c559-68d2-44c3-8de9-860c34a00d81

libsrc/apple2/dioopen.s

@@ -5,7 +5,7 @@
 ;
 
         .export 	_dio_open
-        .import 	return0, __dos_type
+        .import 	return0, __dos_type, isdevice
 
         .include	"errno.inc"
         .include	"mli.inc"
@@ -17,19 +17,22 @@ _dio_open:
         lda	#$01		; "Bad system call number"
         bne	oserr		; Branch always
 
-        ; Walk device list
-:       ldx	DEVCNT
-:       cmp	DEVLST,x
-        beq	:+		; Found drive_id in device list
-        dex
-        bpl	:-
+        ; Check for valid device
+:       tax
+        jsr	isdevice
+        beq	:+
         lda	#$28		; "No device connected"
-        
+
         ; Return oserror
 oserr:  sta	__oserror
         jmp	return0
 
         ; Return success
-:       ldx	#$00
+:       txa
+        asl
+        asl
+        asl
+        asl
+        ldx	#$00
         stx	__oserror
         rts