6502/cc65
1
0
Fork 0
mirror of https://github.com/cc65/cc65.git synced 2025-01-11 11:30:13 +00:00
Code Issues Projects Releases Wiki Activity

Marco van den Heuvel contributed code to detect a C64 DTV.

Browse Source 
git-svn-id: svn://svn.cc65.org/cc65/trunk@4570 b7a2c559-68d2-44c3-8de9-860c34a00d81
This commit is contained in:
uz 2010-02-01 18:04:14 +00:00
parent 1524b0c13f
commit 7d731dce02
1 changed files with 24 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

28
libsrc/c64/get_ostype.s
View File

@ -1,6 +1,9 @@
;
; Stefan Haubenthal, Jul 10 2003
;
; C64DTV detection by
; Marco van den Heuvel, 2010-01-28
;
; unsigned char get_ostype(void)
;
; $AA US
@ -8,16 +11,33 @@
; $43 SX-64
; $03 EU_NEW
; $00 EU_OLD
; $FF C64DTV
;
.export _get_ostype
.proc _get_ostype
ldx #$00 ; Clear high byte
lda $ff80
ldx #0 ; Clear high byte
ldy #1
sty $d03f
ldy $d040
cpy $d000
bne @c64dtv
inc $d000
cpy $d040
beq @c64dtv
; Normal C64
lda $ff80
rts
; C64 DTV
@c64dtv:
stx $d03f
lda #$ff
rts
.endproc