diff --git a/vaporlock/doubledouble/Makefile b/vaporlock/doubledouble/Makefile
index 7f27802b..2f085188 100644
--- a/vaporlock/doubledouble/Makefile
+++ b/vaporlock/doubledouble/Makefile
@@ -23,7 +23,8 @@ DOUBLE:	double.o
 	ld65 -o DOUBLE double.o -C $(LINKERSCRIPTS)/apple2_1000.inc
 
 double.o:	double.s \
-	zp.inc
+	zp.inc hardware.inc pt3_lib_mockingboard_detect.s \
+	pt3_lib_mockingboard_setup.s pt3_lib_detect_model.s
 	ca65 -o double.o double.s -l double.lst
 
 ###
diff --git a/vaporlock/doubledouble/double.s b/vaporlock/doubledouble/double.s
index 9dab9830..80349c4d 100644
--- a/vaporlock/doubledouble/double.s
+++ b/vaporlock/doubledouble/double.s
@@ -5,10 +5,55 @@
 .include "zp.inc"
 .include "hardware.inc"
 
+
+double:
+
+	;================================
+	; detect model
+	;================================
+
+	jsr	detect_appleii_model
+
+
+	;===================
+	; machine workarounds
+	;===================
+	; mostly IIgs
+	;===================
+	; thanks to 4am who provided this code from Total Replay
+
+	lda	ROM_MACHINEID
+	cmp	#$06
+	bne	not_a_iigs
+	sec
+	jsr	$FE1F			; check for IIgs
+	bcs	not_a_iigs
+
+	; gr/text page2 handling broken on early IIgs models
+	; this enables the workaround
+
+	jsr	ROM_TEXT2COPY		; set alternate display mode on IIgs
+	cli				; enable VBL interrupts
+
+
+	; also set background color to black instead of blue
+	lda     NEWVIDEO
+	and     #%00011111	; bit 7 = 0 -> IIgs Apple II-compat video modes
+				; bit 6 = 0 -> IIgs 128K memory map same as IIe
+				; bit 5 = 0 -> IIgs DHGR is color, not mono
+				; bits 0-4 unchanged
+	sta	NEWVIDEO
+	lda	#$F0
+	sta	TBCOLOR			; white text on black background
+	lda	#$00
+	sta	CLOCKCTL		; black border
+	sta	CLOCKCTL		; set twice for VidHD
+
+not_a_iigs:
+
 	;================================
 	; Clear screen and setup graphics
 	;================================
-double:
 
 	jsr	SETGR		; set lo-res 40x40 mode
 
@@ -277,3 +322,8 @@ line_loop_it:
 	bne	line_loop_it
 
 	rts
+
+
+	.include "pt3_lib_detect_model.s"
+;	.include "pt3_lib_mockingboard_setup.s"
+;	.include "pt3_lib_mockingboard_detect.s"
diff --git a/vaporlock/doubledouble/hardware.inc b/vaporlock/doubledouble/hardware.inc
index d065ba19..4ef078c4 100644
--- a/vaporlock/doubledouble/hardware.inc
+++ b/vaporlock/doubledouble/hardware.inc
@@ -5,6 +5,10 @@ EIGHTYSTORE	=	$C001
 CLR80COL	=	$C00C
 SET80COL	=	$C00D
 
+TBCOLOR		=	$C022	; IIgs text foreground / background colors
+CLOCKCTL	=	$C034	; bits 0-3 are IIgs border color
+NEWVIDEO	=	$C029	; IIgs graphics modes
+
 SET_GR	= $C050
 SET_TEXT= $C051
 FULLGR	= $C052
@@ -26,3 +30,5 @@ HPOSN	= $F411
 HPLOT0  = $F457		; plot at (Y,X), (A)
 HGLIN	= $F53A		; line to (X,A),(Y)
 
+ROM_TEXT2COPY	= $F962		; iigs
+ROM_MACHINEID	= $FBB3		; iigs
diff --git a/vaporlock/doubledouble/zp.inc b/vaporlock/doubledouble/zp.inc
index 898c3c0c..351a0a05 100644
--- a/vaporlock/doubledouble/zp.inc
+++ b/vaporlock/doubledouble/zp.inc
@@ -3,8 +3,13 @@ GBASL	= $26
 GBASH	= $27
 V2	= $2D
 
+APPLEII_MODEL	= $8B
+
 HGRPAGE = $E6
 
-YPOS	= $FE
-TCOLOR	= $FF
+MB_VALUE	= $F5
+MB_ADDR_L	= $F6
+MB_ADDR_H	= $F7
+YPOS		= $FE
+TCOLOR		= $FF