determines OS version

git-svn-id: svn://svn.cc65.org/cc65/trunk@146 b7a2c559-68d2-44c3-8de9-860c34a00d81

diff --git a/libsrc/atari/ostype.s b/libsrc/atari/ostype.s
new file mode 100644 (file)
index 0000000..7975c8b
--- /dev/null
+++ b/libsrc/atari/ostype.s
@@ -0,0 +1,161 @@
+;
+; Christian Groessler, July 2000
+; from Freddy Offenga's rominfo.c
+;
+; unsigned int get_ostype(void)
+;
+; x x x x x x x x  x x x x x x x x   - 16 bit flag
+; | | | | | | | |  | | | | | | | |
+; | | | | | | | |  | | | | | +-+-+-- main OS rev.
+; | | | | | | | |  | | | +-+-------- PAL/NTSC flag
+; | | | | | | | |  +-+-+------------ minor OS rev.
+; +-+-+-+-+-+-+-+------------------- unused
+;
+; main OS rev.:
+;      000 - unknown
+;      001 - 400/800 ROM
+;      010 - 1200XL ROM
+;      011 - XL/XE ROM
+;      1xx - unassigned
+; PAL/NTSC flag:
+;      00 - unknown
+;      01 - PAL
+;      10 - NTSC
+;      11 - (invalid)
+; minor OS rev.: (depending on main OS rev.);
+;      400/800:
+;              000 - unknown
+;              001 - Rev. A
+;              010 - Rev. B
+;              011 - unassigned (up to 111)
+;      1200XL:
+;              000 - unknown
+;              001 - Rev. 10
+;              010 - Rev. 11
+;              011 - unassigned (up to 111)
+;      XL/XE:
+;              000 - unknown
+;              001 - Rev. 1
+;              010 - Rev. 2
+;              011 - Rev. 3
+;              100 - Rev. 4
+;              101 - unassigned (up to 111)
+;
+
+
+       .include        "atari.inc"
+       .export         _get_ostype
+
+.proc  _get_ostype
+
+       lda     $fcd8
+       cmp     #$a2
+       beq     _400800
+       lda     $fff1
+       cmp     #1
+       beq     _1200xl
+       lda     $fff7
+       cmp     #1
+       bcc     _unknown
+       cmp     #5
+       bcs     _unknown
+
+;XL/XE ROM
+
+       sec
+       asl     a
+       asl     a
+       asl     a
+       asl     a
+       asl     a
+       ora     #%11
+_fin:  ldx     #0
+       rts
+
+; unknown ROM
+
+_unknown:
+       lda     #0
+       tax
+       rts
+
+; 1200XL ROM
+
+_1200xl:
+       lda     $fff7           ; revision #
+       cmp     #10
+       beq     _1200_10
+       cmp     #11
+       beq     _1200_11
+       lda     #0              ; for unknown
+       beq     _1200_fin
+
+_1200_10:
+       lda     #%00100000
+       bne     _1200_fin
+
+_1200_11:
+       lda     #%01000000
+
+_1200_fin:
+       ora     #%010
+       bne     _fin
+
+; 400/800 ROM
+
+_400800:
+       lda     $fff8
+       ldx     $fff9
+       cmp     #$dd
+       bne     _400800_1
+       cpx     #$57
+       bne     _400800_unknown
+
+; 400/800 NTSC Rev. A
+
+       lda     #%00110001
+       bne     _400800_done
+
+; 400/900 unknown
+
+_400800_unknown:
+       lda     #%00000001
+       bne     _400800_done
+
+_400800_1:
+       cmp     #$d6
+       bne     _400800_2
+       cpx     #$57
+       bne     _400800_unknown
+
+; 400/800 PAL Rev. A
+
+       lda     #%00101001
+       bne     _400800_done
+
+_400800_2:
+       cmp     #$f3
+       bne     _400800_3
+       cpx     #$e6
+       bne     _400800_unknown
+
+; 400/800 NTSC Rev. B
+
+       lda     #%01010001
+       bne     _400800_done
+
+_400800_3:
+
+       cmp     #$22
+       bne     _400800_unknown
+       cpx     #$58
+       bne     _400800_unknown
+
+; 400/800 PAL Rev. B
+
+       lda     #%01001001
+
+_400800_done:
+       bne     _fin
+
+.endproc