From 8b6a40c04e0a5fefacd3a4351101b239a1c4e8b6 Mon Sep 17 00:00:00 2001
From: uz <uz@b7a2c559-68d2-44c3-8de9-860c34a00d81>
Date: Sat, 27 Feb 2010 14:46:43 +0000
Subject: [PATCH] Patch by Marco van den Heuvel that adds detection of GEOS 1.1
 and the plus4 GEOS to the get_ostype function.

git-svn-id: svn://svn.cc65.org/cc65/trunk@4600 b7a2c559-68d2-44c3-8de9-860c34a00d81
---
 include/geos/gsys.h             |  4 +++-
 libsrc/geos/system/get_ostype.s | 38 ++++++++++++++++++++++++++++-----
 2 files changed, 36 insertions(+), 6 deletions(-)

diff --git a/include/geos/gsys.h b/include/geos/gsys.h
index ff150191d..493c2609f 100644
--- a/include/geos/gsys.h
+++ b/include/geos/gsys.h
@@ -28,10 +28,12 @@ char get_ostype(void);
    be combined with OR */
   /* machine flags */
 #define GEOS64		0x00
+#define GEOS4           0x04    /* plus4 geos is not or'ed with version */
 #define GEOS128		0x80
   /* version flags */
 #define GEOS_V10	0x10
-#define GEOS_V12	0x12	/* ??? not sure */
+#define GEOS_V11        0x11
+#define GEOS_V12	0x12   	/* ??? not sure */
 #define GEOS_V20	0x20
 #define WHEELS		0x40	/* only Wheels? */
 
diff --git a/libsrc/geos/system/get_ostype.s b/libsrc/geos/system/get_ostype.s
index ea6801e5c..342b16c6b 100644
--- a/libsrc/geos/system/get_ostype.s
+++ b/libsrc/geos/system/get_ostype.s
@@ -1,8 +1,12 @@
-
+                                        
 ;
 ; Maciej 'YTM/Elysium' Witkowiak
 ;
 ; 10.09.2001
+;
+; Plus4 and GEOS 1.1 detection by
+; Marco van den Heuvel, 2010-02-02
+;
 
 ; unsigned char get_ostype (void);
 ; unsigned char get_tv (void);
@@ -18,18 +22,30 @@
 _get_ostype:
 	    ldx #0
 	    lda version
+	    cmp #$a9
+	    beq geos11
 	    and #%11110000
 	    cmp #$10
 	    beq geos10
 	    lda c128Flag		; we're on at least 2.0
+	    cmp #$18
+	    beq geos_on_plus4
 	    ora version
 	    rts
 geos10:
 	    lda version
 	    rts
+geos11:
+	    lda #$11
+	    rts
+geos_on_plus4:
+	    lda #$04
+	    rts
 
 _get_tv:
 	    jsr _get_ostype
+	    cmp #$04
+	    beq plus4_get_tv
 	    bpl only40			; C64 with 40 columns only
 	    lda graphMode
 	    bpl only40			; C128 but currently on 40 columns
@@ -43,18 +59,21 @@ tvmode:					; PAL/NTSC check here, result in A
 	    pha
 	    lda #IO_IN			; enable access to I/O
 	    sta CPU_DATA
-            bit rasreg
+	    bit rasreg
 	    bpl tvmode			; wait for rasterline  127<x<256
 	    lda #24			; (rasterline now >=256!)
-modelp:	    cmp rasreg			; wait for rasterline = 24 (or 280 on PAL)
+modelp:
+	    cmp rasreg			; wait for rasterline = 24 (or 280 on PAL)
 	    bne modelp
 	    lda grcntrl1		; 24 or 280 ?
 	    bpl ntsc
 	    lda #0			; PAL
 	    beq modeend
-ntsc:	    lda #$80			; NTSC
+ntsc:
+	    lda #$80			; NTSC
 
-modeend:    stx tmp1
+modeend:
+	    stx tmp1
 	    ora tmp1
 	    sta tmp1
 	    ldx #0
@@ -63,3 +82,12 @@ modeend:    stx tmp1
 	    plp                         ; restore interrupt state
 	    lda tmp1
 	    rts
+plus4_get_tv:
+	    ldx #1			; Assume PAL
+	    bit $FF07		        ; Test bit 6
+	    bvc plus4pal
+	    dex			        ; NTSC
+plus4pal:
+	    txa
+	    ldx #0
+	    rts
-- 
2.39.2