Index: include/hwdefs.h
===================================================================
--- include/hwdefs.h	(revision d60f436ae355378a9cc7229dd74e18a9625c185a)
+++ include/hwdefs.h	(revision c59409ecb4964b2dfc1b86fabb892798f7c896e7)
@@ -12,45 +12,45 @@
 /* hardware addresses */
 
-extern	uint16_t	io_fpu[];	/* 0x180000 */
-extern	uint8_t		io_time[];	/* 0x3a0001 */
-extern	uint8_t		io_lcd;		/* 0x3a4001 */
-extern	uint8_t		io_ser;		/* 0x3a8001 */
-extern	uint8_t		io_midi;	/* 0x3ac001 */
-extern	uint8_t		io_disk;	/* 0x3b0001 */
-extern	uint8_t		io_tone;	/* 0x3b4001 */
-extern	uint8_t		io_leds;	/* 0x3b8001 */
-extern	uint8_t		io_kbrd;	/* 0x3bc001 */
-extern	uint8_t		lcd_a0;		/* io_lcd + 0 */
-extern	uint8_t		lcd_a1;		/* io_lcd + 2 */
+extern	volatile uint16_t	io_fpu[];	/* 0x180000 */
+extern	volatile uint8_t	io_time[];	/* 0x3a0001 */
+extern	volatile uint8_t	io_lcd;		/* 0x3a4001 */
+extern	volatile uint8_t	io_ser;		/* 0x3a8001 */
+extern	volatile uint8_t	io_midi;	/* 0x3ac001 */
+extern	volatile uint8_t	io_disk;	/* 0x3b0001 */
+extern	volatile uint8_t	io_tone;	/* 0x3b4001 */
+extern	volatile uint8_t	io_leds;	/* 0x3b8001 */
+extern	volatile uint8_t	io_kbrd;	/* 0x3bc001 */
+extern	volatile uint8_t	lcd_a0;		/* io_lcd + 0 */
+extern	volatile uint8_t	lcd_a1;		/* io_lcd + 2 */
 
-extern	uint16_t	io_vreg[];	/* 0x200000 Video registers after setup */
-extern	uint16_t	io_vraw[];	/* 0x200400 Video registers after reset */
-extern	uint16_t	io_vram[];	/* 0x200000 Video RAM */
+extern	volatile uint16_t	io_vreg[];	/* 0x200000 Video registers after setup */
+extern	volatile uint16_t	io_vraw[];	/* 0x200400 Video registers after reset */
+extern	volatile uint16_t	io_vram[];	/* 0x200000 Video RAM */
 
 /* video memory allocations, bank 0 */
 
-extern	uint16_t	v_regs[];	/* 0x200000 Video registers */
-extern	uint16_t	v_odtab[][4];	/* 0x200080 Object Descriptor Table */
-extern	uint16_t	v_actab[];	/* 0x200100 Access Table */
-extern	uint16_t	v_ct0[];	/* 0x200400 */
-extern	uint16_t	v_gt1[];	/* 0x200518 */
-extern	uint16_t	v_score[];	/* 0x202000 Score */
-extern	uint16_t	v_cgtab[];	/* 0x21e000 Character Generator */
+extern	volatile uint16_t	v_regs[];	/* 0x200000 Video registers */
+extern	volatile uint16_t	v_odtab[][4];	/* 0x200080 Object Descriptor Table */
+extern	volatile uint16_t	v_actab[];	/* 0x200100 Access Table */
+extern	volatile uint16_t	v_ct0[];	/* 0x200400 */
+extern	volatile uint16_t	v_gt1[];	/* 0x200518 */
+extern	volatile uint16_t	v_score[];	/* 0x202000 Score */
+extern	volatile uint16_t	v_cgtab[];	/* 0x21e000 Character Generator */
 
 /* video memory allocations, bank 1 */
 
-extern	uint16_t	v_curs0[];	/* 0x200400 ULE cursor */
-extern	uint16_t	v_curs1[];	/* 0x200480 ULO cursor */
-extern	uint16_t	v_curs2[];	/* 0x200500 URE cursor */
-extern	uint16_t	v_curs3[];	/* 0x200580 URO cursor */
-extern	uint16_t	v_curs4[];	/* 0x200600 LLE cursor */
-extern	uint16_t	v_curs5[];	/* 0x200680 LLO cursor */
-extern	uint16_t	v_curs6[];	/* 0x200700 LRE cursor */
-extern	uint16_t	v_curs7[];	/* 0x200780 LRO cursor */
-extern	uint16_t	v_tcur[];	/* 0x200800 Typewriter */
-extern	uint16_t	v_kbobj[];	/* 0x200b40 Keyboard */
-extern	uint16_t	v_lnobj[];	/* 0x201240 Line */
-extern	uint16_t	v_cur[];	/* 0x201940 Underline cursor */
-extern	uint16_t	v_win0[];	/* 0x204000 Window 0 */
+extern	volatile uint16_t	v_curs0[];	/* 0x200400 ULE cursor */
+extern	volatile uint16_t	v_curs1[];	/* 0x200480 ULO cursor */
+extern	volatile uint16_t	v_curs2[];	/* 0x200500 URE cursor */
+extern	volatile uint16_t	v_curs3[];	/* 0x200580 URO cursor */
+extern	volatile uint16_t	v_curs4[];	/* 0x200600 LLE cursor */
+extern	volatile uint16_t	v_curs5[];	/* 0x200680 LLO cursor */
+extern	volatile uint16_t	v_curs6[];	/* 0x200700 LRE cursor */
+extern	volatile uint16_t	v_curs7[];	/* 0x200780 LRO cursor */
+extern	volatile uint16_t	v_tcur[];	/* 0x200800 Typewriter */
+extern	volatile uint16_t	v_kbobj[];	/* 0x200b40 Keyboard */
+extern	volatile uint16_t	v_lnobj[];	/* 0x201240 Line */
+extern	volatile uint16_t	v_cur[];	/* 0x201940 Underline cursor */
+extern	volatile uint16_t	v_win0[];	/* 0x204000 Window 0 */
 
 /* stuff in the depths of the bios */