diff --git a/src/intel_piix.c b/src/intel_piix.c
index 08c71a6a5..4fc3ac0d6 100644
--- a/src/intel_piix.c
+++ b/src/intel_piix.c
@@ -10,13 +10,13 @@
  *		    word 0 - base address
  *		    word 1 - bits 1-15 = byte count, bit 31 = end of transfer
  *
- * Version:	@(#)intel_piix.c	1.0.10	2017/12/15
+ * Version:	@(#)intel_piix.c	1.0.11	2018/02/01
  *
  * Authors:	Sarah Walker, <http://pcem-emulator.co.uk/>
  *		Miran Grca, <mgrca8@gmail.com>
  *
- *		Copyright 2008-2017 Sarah Walker.
- *		Copyright 2016,2017 Miran Grca.
+ *		Copyright 2008-2018 Sarah Walker.
+ *		Copyright 2016-2018 Miran Grca.
  */
 #include <stdio.h>
 #include <stdint.h>
@@ -104,11 +104,10 @@ void piix_write(int func, int addr, uint8_t val, void *priv)
                 if (addr == 4 || (addr & ~3) == 0x20) /*Bus master base address*/                
                 {
                         uint16_t base = (card_piix_ide[0x20] & 0xf0) | (card_piix_ide[0x21] << 8);
-                        io_removehandler(old_base, 0x10, piix_bus_master_read, NULL, NULL, piix_bus_master_write, NULL, NULL,  NULL);
-                        if (card_piix_ide[0x04] & 1)
-			{
+			if (old_base)
+	                        io_removehandler(old_base, 0x10, piix_bus_master_read, NULL, NULL, piix_bus_master_write, NULL, NULL,  NULL);
+                        if ((card_piix_ide[0x04] & 1) && base)
 				io_sethandler(base, 0x10, piix_bus_master_read, NULL, NULL, piix_bus_master_write, NULL, NULL,  NULL);
-			}
                 }
         }
         else
@@ -638,8 +637,17 @@ void piix_bus_master_set_irq(int channel)
 }
 
 
+static void piix_bus_master_reset(void)
+{
+	uint16_t old_base = (card_piix_ide[0x20] & 0xf0) | (card_piix_ide[0x21] << 8);
+	if (old_base)
+		io_removehandler(old_base, 0x10, piix_bus_master_read, NULL, NULL, piix_bus_master_write, NULL, NULL,  NULL);
+}
+
+
 void piix_reset(void)
 {
+	piix_bus_master_reset();
         memset(card_piix, 0, 256);
         card_piix[0x00] = 0x86; card_piix[0x01] = 0x80; /*Intel*/
         card_piix[0x02] = 0x2e; card_piix[0x03] = 0x12; /*82371FB (PIIX)*/
@@ -681,6 +689,7 @@ void piix_reset(void)
 
 void piix3_reset(void)
 {
+	piix_bus_master_reset();
         memset(card_piix, 0, 256);
         card_piix[0x00] = 0x86; card_piix[0x01] = 0x80; /*Intel*/
         card_piix[0x02] = 0x00; card_piix[0x03] = 0x70; /*82371SB (PIIX3)*/
diff --git a/src/io.c b/src/io.c
index 050733261..4fee6cdbd 100644
--- a/src/io.c
+++ b/src/io.c
@@ -8,17 +8,18 @@
  *
  *		Implement I/O ports and their operations.
  *
- * Version:	@(#)io.c	1.0.1	2017/12/16
+ * Version:	@(#)io.c	1.0.2	2018/02/01
  *
  * Authors:	Sarah Walker, <http://pcem-emulator.co.uk/>
  *		Miran Grca, <mgrca8@gmail.com>
  *		Fred N. van Kempen, <decwiz@yahoo.com>
  *
- *		Copyright 2008-2017 Sarah Walker.
- *		Copyright 2016,2017 Miran Grca.
+ *		Copyright 2008-2018 Sarah Walker.
+ *		Copyright 2016-2018 Miran Grca.
  */
 #include <stdio.h>
 #include <stdint.h>
+#include <stdlib.h>
 #include <string.h>
 #include <wchar.h>
 #include "86box.h"
@@ -29,36 +30,22 @@
 #define NPORTS		65536		/* PC/AT supports 64K ports */
 
 
-/*
- * This should be redone using a
- *
- * typedef struct _io_ {
- *	uint8_t  (*inb)(uint16_t addr, void *priv);
- *	uint16_t (*inw)(uint16_t addr, void *priv);
- *	uint32_t (*inl)(uint16_t addr, void *priv);
- *
- *	void     (*outb)(uint16_t addr, uint8_t  val, void *priv);
- *	void     (*outw)(uint16_t addr, uint16_t val, void *priv);
- *	void     (*outl)(uint16_t addr, uint32_t val, void *priv);
- *
- *	void	*priv;
- *
- *	struct _io_ *next;
- * } io_t;
- *
- * at some point. We keep one base entry per I/O port, and if
- * more than one entry is needed (some ports are like that),
- * we just add a handler to the list for that port.
- */
-static uint8_t  (*port_inb[NPORTS][2])(uint16_t addr, void *priv);
-static uint16_t (*port_inw[NPORTS][2])(uint16_t addr, void *priv);
-static uint32_t (*port_inl[NPORTS][2])(uint16_t addr, void *priv);
+typedef struct _io_ {
+	uint8_t  (*inb)(uint16_t addr, void *priv);
+	uint16_t (*inw)(uint16_t addr, void *priv);
+	uint32_t (*inl)(uint16_t addr, void *priv);
 
-static void (*port_outb[NPORTS][2])(uint16_t addr, uint8_t  val, void *priv);
-static void (*port_outw[NPORTS][2])(uint16_t addr, uint16_t val, void *priv);
-static void (*port_outl[NPORTS][2])(uint16_t addr, uint32_t val, void *priv);
+	void     (*outb)(uint16_t addr, uint8_t  val, void *priv);
+	void     (*outw)(uint16_t addr, uint16_t val, void *priv);
+	void     (*outl)(uint16_t addr, uint32_t val, void *priv);
 
-static void *port_priv[NPORTS][2];
+	void	*priv;
+
+	struct _io_ *prev, *next;
+} io_t;
+
+int initialized = 0;
+io_t *io[NPORTS], *io_last[NPORTS];
 
 
 #ifdef IO_CATCH
@@ -75,25 +62,45 @@ void
 io_init(void)
 {
     int c;
+    io_t *p, *q;
+
+    if (!initialized) {
+	for (c=0; c<NPORTS; c++)
+		io[c] = NULL;
+	initialized = 1;
+    }
 
-    pclog("IO: initializing\n");
     for (c=0; c<NPORTS; c++) {
+        if (io_last[c]) {
+		/* Port c has at least one handler. */
+		p = io_last[c];
+		/* After this loop, p will have the pointer to the first handler. */
+		while (p) {
+			q = p->prev;
+			free(p);
+			p = q;
+		}
+		p = NULL;
+	}
+
 #ifdef IO_CATCH
-	port_inb[c][0]  = port_inb[c][1]  = null_inb;
-	port_outb[c][0] = port_outb[c][1] = null_outb;
-	port_inw[c][0]  = port_inw[c][1]  = null_inw;
-	port_outw[c][0] = port_outw[c][1] = null_outw;
-	port_inl[c][0]  = port_inl[c][1]  = null_inl;
-	port_outl[c][0] = port_outl[c][1] = null_outl;
+	/* io[c] should be the only handler, pointing at the NULL catch handler. */
+	p = (io_t *) malloc(sizeof(io_t));
+	memset(p, 0, sizeof(io_t));
+	io[c] = p;
+	p->next = NULL;
+	p->prev = NULL;
+	p->inb  = null_inb;
+	p->outb = null_outb;
+	p->inw  = null_inw;
+	p->outw = null_outw;
+	p->inl  = null_inl;
+	p->outl = null_outl;
+	p->priv = NULL;
 #else
-	port_inb[c][0]  = port_inb[c][1]  = NULL;
-	port_outb[c][0] = port_outb[c][1] = NULL;
-	port_inw[c][0]  = port_inw[c][1]  = NULL;
-	port_outw[c][0] = port_outw[c][1] = NULL;
-	port_inl[c][0]  = port_inl[c][1]  = NULL;
-	port_outl[c][0] = port_outl[c][1] = NULL;
+	/* io[c] should be NULL. */
+	io[c] = NULL;
 #endif
-	port_priv[c][0] = port_priv[c][1] = NULL;
     }
 }
 
@@ -109,33 +116,32 @@ io_sethandler(uint16_t base, int size,
 	      void *priv)
 {
     int c;
+    io_t *p, *q = NULL;
 
-    for (c=0; c<size; c++) {
-	if (!port_inb[base+c][0] && !port_inw[base+c][0] &&
-	    !port_inl[base+c][0] && !port_outb[base+c][0] &&
-	    !port_outw[base+c][0] && !port_outl[base+c][0]) {
-		port_inb[base+c][0] = inb;
-		port_inw[base+c][0] = inw;
-		port_inl[base+c][0] = inl;
-
-		port_outb[base+c][0] = outb;
-		port_outw[base+c][0] = outw;
-		port_outl[base+c][0] = outl;
-
-		port_priv[base+c][0] = priv;
-	} else if (!port_inb[base+c][1] && !port_inw[base+c][1] &&
-		   !port_inl[base+c][1] && !port_outb[base+c][1] &&
-		   !port_outw[base+c][1] && !port_outl[base+c][1]) {
-		port_inb[base+c][1] = inb;
-		port_inw[base+c][1] = inw;
-		port_inl[base+c][1] = inl;
-
-		port_outb[base+c][1] = outb;
-		port_outw[base+c][1] = outw;
-		port_outl[base+c][1] = outl;
-
-		port_priv[base+c][1] = priv;
+    for (c = 0; c < size; c++) {
+	p = io_last[base + c];
+	q = (io_t *) malloc(sizeof(io_t));
+	memset(q, 0, sizeof(io_t));
+	if (p) {
+		p->next = q;
+		q->prev = p;
+	} else {
+		io[base + c] = q;
+		q->prev = NULL;
 	}
+
+	q->inb = inb;
+	q->inw = inw;
+	q->inl = inl;
+
+	q->outb = outb;
+	q->outw = outw;
+	q->outl = outl;
+
+	q->priv = priv;
+	q->next = NULL;
+
+	io_last[base + c] = q;
     }
 }
 
@@ -151,37 +157,30 @@ io_removehandler(uint16_t base, int size,
 	void *priv)
 {
     int c;
+    io_t *p;
 
-    for (c=0; c<size; c++) {
-	if (port_priv[base+c][0] == priv) {
-		if (port_inb[base+c][0] == inb)
-			port_inb[ base + c][0] = NULL;
-		if (port_inw[base+c][0] == inw)
-			port_inw[ base + c][0] = NULL;
-		if (port_inl[base+c][0] == inl)
-			port_inl[base+c][0] = NULL;
-		if (port_outb[base+c][0] == outb)
-			port_outb[base + c][0] = NULL;
-		if (port_outw[base+c][0] == outw)
-			port_outw[base + c][0] = NULL;
-		if (port_outl[base+c][0] == outl)
-			port_outl[base+c][0] = NULL;
-		port_priv[base+c][0] = NULL;
-	}
-	if (port_priv[base+c][1] == priv) {
-		if (port_inb[base+c][1] == inb)
-		port_inb[ base+c][1] = NULL;
-		if (port_inw[base+c][1] == inw)
-		port_inw[ base+c][1] = NULL;
-		if (port_inl[base+c][1] == inl)
-		port_inl[base+c][1] = NULL;
-		if (port_outb[base+c][1] == outb)
-		port_outb[base+c][1] = NULL;
-		if (port_outw[base+c][1] == outw)
-		port_outw[base+c][1] = NULL;
-		if (port_outl[base+c][1] == outl)
-		port_outl[base+c][1] = NULL;
-		port_priv[base+c][1] = NULL;
+    for (c = 0; c < size; c++) {
+	p = io[base + c];
+	if (!p)
+		continue;
+	while(p) {
+		if ((p->inb == inb) && (p->inw == inw) &&
+		    (p->inl == inl) && (p->outb == outb) &&
+		    (p->outw == outw) && (p->outl == outl) &&
+		    (p->priv == priv)) {
+			if (p->prev)
+				p->prev->next = p->next;
+			else
+				io[base + c] = p->next;
+			if (p->next)
+				p->next->prev = p->prev;
+			else
+				io_last[base + c] = p->prev;
+			free(p);
+			p = NULL;
+			break;
+		}
+		p = p->next;
 	}
     }
 }
@@ -199,32 +198,30 @@ io_sethandler_interleaved(uint16_t base, int size,
 	void *priv)
 {
     int c;
+    io_t *p, *q;
 
     size <<= 2;
     for (c=0; c<size; c+=2) {
-	if (!port_inb[base+c][0] && !port_inw[base+c][0] &&
-	    !port_inl[base+c][0] && !port_outb[base+c][0] &&
-	    !port_outw[base+c][0] && !port_outl[base+c][0]) {
-		port_inb[ base + c][0] = inb;
-		port_inw[ base + c][0] = inw;
-		port_inl[ base + c][0] = inl;
-		port_outb[base + c][0] = outb;
-		port_outw[base + c][0] = outw;
-		port_outl[base + c][0] = outl;
-		port_priv[base + c][0] = priv;
-	} else if (!port_inb[base+c][1] && !port_inw[base+c][1] &&
-		   !port_inl[base+c][1] && !port_outb[base+c][1] &&
-		   !port_outw[base+c][1] && !port_outl[base+c][1]) {
-		port_inb[ base + c][1] = inb;
-		port_inw[ base + c][1] = inw;
-		port_inl[ base + c][1] = inl;
-
-		port_outb[base + c][1] = outb;
-		port_outw[base + c][1] = outw;
-		port_outl[base + c][1] = outl;
-
-		port_priv[base + c][1] = priv;
+	p = last_handler(base + c);
+	q = (io_t *) malloc(sizeof(io_t));
+	memset(q, 0, sizeof(io_t));
+	if (p) {
+		p->next = q;
+		q->prev = p;
+	} else {
+		io[base + c] = q;
+		q->prev = NULL;
 	}
+
+	q->inb = inb;
+	q->inw = inw;
+	q->inl = inl;
+
+	q->outb = outb;
+	q->outw = outw;
+	q->outl = outl;
+
+	q->priv = priv;
     }
 }
 
@@ -240,38 +237,26 @@ io_removehandler_interleaved(uint16_t base, int size,
 	void *priv)
 {
     int c;
+    io_t *p;
 
     size <<= 2;
-    for (c=0; c<size; c+=2) {
-	if (port_priv[base+c][0] == priv) {
-		if (port_inb[base+c][0] == inb)
-			port_inb[base+c][0] = NULL;
-		if (port_inw[base+c][0] == inw)
-			port_inw[base+c][0] = NULL;
-		if (port_inl[base+c][0] == inl)
-			port_inl[base+c][0] = NULL;
-		if (port_outb[base+c][0] == outb)
-			port_outb[base+c][0] = NULL;
-		if (port_outw[base+c][0] == outw)
-			port_outw[base+c][0] = NULL;
-		if (port_outl[base+c][0] == outl)
-			port_outl[base+c][0] = NULL;
-		port_priv[base+c][0] = NULL;
-	}
-	if (port_priv[base+c][1] == priv) {
-		if (port_inb[base+c][1] == inb)
-			port_inb[base+c][1] = NULL;
-		if (port_inw[base+c][1] == inw)
-			port_inw[base+c][1] = NULL;
-		if (port_inl[base+c][1] == inl)
-			port_inl[base+c][1] = NULL;
-		if (port_outb[base+c][1] == outb)
-			port_outb[base+c][1] = NULL;
-		if (port_outw[base+c][1] == outw)
-			port_outw[base+c][1] = NULL;
-		if (port_outl[base+c][1] == outl)
-			port_outl[base+c][1] = NULL;
-		port_priv[base+c][1] = NULL;
+    for (c = 0; c < size; c += 2) {
+	p = io[base + c];
+	if (!p)
+		return;
+	while(p) {
+		if ((p->inb == inb) && (p->inw == inw) &&
+		    (p->inl == inl) && (p->outb == outb) &&
+		    (p->outw == outw) && (p->outl == outl) &&
+		    (p->priv == priv)) {
+			if (p->prev)
+				p->prev->next = p->next;
+			if (p->next)
+				p->next->prev = p->prev;
+			free(p);
+			break;
+		}
+		p = p->next;
 	}
     }
 }
@@ -282,11 +267,16 @@ uint8_t
 inb(uint16_t port)
 {
     uint8_t r = 0xff;
+    io_t *p;
 
-    if (port_inb[port][0])
-	r &= port_inb[port][0](port, port_priv[port][0]);
-    if (port_inb[port][1])
-	r &= port_inb[port][1](port, port_priv[port][1]);
+    p = io[port];
+    if (p) {
+	while(p) {
+		if (p->inb)
+			r &= p->inb(port, p->priv);
+		p = p->next;
+	}
+    }
 
 #ifdef IO_TRACE
     if (CS == IO_TRACE)
@@ -300,25 +290,38 @@ inb(uint16_t port)
 void
 outb(uint16_t port, uint8_t val)
 {
-    if (port_outb[port][0])
-	port_outb[port][0](port, val, port_priv[port][0]);
-    if (port_outb[port][1])
-	port_outb[port][1](port, val, port_priv[port][1]);
+    io_t *p;
+
+    if (io[port]) {
+	p = io[port];
+	while(p) {
+		if (p->outb)
+			p->outb(port, val, p->priv);
+		p = p->next;
+	}
+    }
 	
 #ifdef IO_TRACE
     if (CS == IO_TRACE)
 	pclog("IOTRACE(%04X): outb(%04x,%02x)\n", IO_TRACE, port, val);
 #endif
+    return;
 }
 
 
 uint16_t
 inw(uint16_t port)
 {
-    if (port_inw[port][0])
-	return(port_inw[port][0](port, port_priv[port][0]));
-    if (port_inw[port][1])
-	return(port_inw[port][1](port, port_priv[port][1]));
+    io_t *p;
+
+    p = io[port];
+    if (p) {
+	while(p) {
+		if (p->inw)
+			return p->inw(port, p->priv);
+		p = p->next;
+	}
+    }
 
     return(inb(port) | (inb(port + 1) << 8));
 }
@@ -327,27 +330,39 @@ inw(uint16_t port)
 void
 outw(uint16_t port, uint16_t val)
 {
-    if (port_outw[port][0]) {
-	port_outw[port][0](port, val, port_priv[port][0]);
-	return;
-    }
-    if (port_outw[port][1]) {
-	port_outw[port][1](port, val, port_priv[port][1]);
-	return;
+    io_t *p;
+
+    p = io[port];
+    if (p) {
+	while(p) {
+		if (p->outw) {
+			p->outw(port, val, p->priv);
+			return;
+		}
+		p = p->next;
+	}
     }
 
     outb(port,val);
     outb(port+1,val>>8);
+
+    return;
 }
 
 
 uint32_t
 inl(uint16_t port)
 {
-    if (port_inl[port][0])
-	return(port_inl[port][0](port, port_priv[port][0]));
-    if (port_inl[port][1])
-	return(port_inl[port][1](port, port_priv[port][1]));
+    io_t *p;
+
+    p = io[port];
+    if (p) {
+	while(p) {
+		if (p->inl)
+			return p->inl(port, p->priv);
+		p = p->next;
+	}
+    }
 
     return(inw(port) | (inw(port + 2) << 16));
 }
@@ -356,15 +371,21 @@ inl(uint16_t port)
 void
 outl(uint16_t port, uint32_t val)
 {
-    if (port_outl[port][0]) {
-	port_outl[port][0](port, val, port_priv[port][0]);
-	return;
-    }
-    if (port_outl[port][1]) {
-	port_outl[port][1](port, val, port_priv[port][1]);
-	return;
+    io_t *p;
+
+    p = io[port];
+    if (p) {
+	while(p) {
+		if (p->outl) {
+			p->outl(port, val, p->priv);
+			return;
+		}
+		p = p->next;
+	}
     }
 
     outw(port, val);
     outw(port + 2, val >> 16);
+
+    return;
 }
diff --git a/src/network/net_ne2000.c b/src/network/net_ne2000.c
index 4049f9dc7..a1524bf0d 100644
--- a/src/network/net_ne2000.c
+++ b/src/network/net_ne2000.c
@@ -14,7 +14,7 @@
  *
  * NOTE:	The file will also implement an NE1000 for 8-bit ISA systems.
  *
- * Version:	@(#)net_ne2000.c	1.0.28	2018/01/28
+ * Version:	@(#)net_ne2000.c	1.0.29	2018/02/01
  *
  * Authors:	Fred N. van Kempen, <decwiz@yahoo.com>
  *		Peter Grehan, <grehan@iprg.nokia.com>
@@ -26,7 +26,7 @@
  *
  *		Portions Copyright (C) 2002  MandrakeSoft S.A.
  *		Portions Copyright (C) 2018  Sarah Walker.
- *		Copyright 2018 Fred N. van Kempen.
+ *		Copyright 2017,2018 Fred N. van Kempen.
  */
 #include <stdio.h>
 #include <stdint.h>
@@ -1764,9 +1764,6 @@ nic_pnp_writeb(uint16_t addr, uint8_t val, void *priv)
 static void
 nic_pnp_io_set(nic_t *dev, uint16_t read_addr)
 {
-	io_sethandler(0x0A79, 1,
-		      NULL, NULL, NULL,
-		      nic_pnp_writeb, NULL, NULL, dev);
 	if ((read_addr >= 0x0200) && (read_addr <= 0x03FF)) {
 		io_sethandler(read_addr, 1,
 			      nic_pnp_readb, NULL, NULL,
@@ -1779,12 +1776,11 @@ nic_pnp_io_set(nic_t *dev, uint16_t read_addr)
 static void
 nic_pnp_io_remove(nic_t *dev)
 {
-	io_removehandler(0x0A79, 1,
-		      NULL, NULL, NULL,
-		      nic_pnp_writeb, NULL, NULL, dev);
-	io_removehandler(dev->pnp_read, 1,
-		      nic_pnp_readb, NULL, NULL,
-		      NULL, NULL, NULL, dev);
+	if ((dev->pnp_read >= 0x0200) && (dev->pnp_read <= 0x03FF)) {
+		io_removehandler(dev->pnp_read, 1,
+			      nic_pnp_readb, NULL, NULL,
+			      NULL, NULL, NULL, dev);
+	}
 }
 
 
@@ -1799,11 +1795,8 @@ nic_pnp_address_writeb(uint16_t addr, uint8_t val, void *priv)
 	case PNP_PHASE_WAIT_FOR_KEY:
 		if (val == pnp_init_key[dev->pnp_magic_count]) {
 			dev->pnp_magic_count = (dev->pnp_magic_count + 1) & 0x1f;
-			if (!dev->pnp_magic_count) {
-				nic_pnp_io_remove(dev);
-				nic_pnp_io_set(dev, dev->pnp_read);
+			if (!dev->pnp_magic_count)
 				dev->pnp_phase = PNP_PHASE_SLEEP;
-			}
 		} else
 			dev->pnp_magic_count = 0;
 		break;
@@ -2592,7 +2585,9 @@ nic_init(device_t *info)
 			dev->eeprom[0x5C] += dev->eeprom[c];
 		dev->eeprom[0x5C] = -dev->eeprom[0x5C];
 
-		nic_pnp_io_set(dev, dev->pnp_read);
+		io_sethandler(0x0A79, 1,
+			      NULL, NULL, NULL,
+			      nic_pnp_writeb, NULL, NULL, dev);
 	}
     }
 
diff --git a/src/sio_um8669f.c b/src/sio_um8669f.c
index 8238ff5b4..1f2dccf11 100644
--- a/src/sio_um8669f.c
+++ b/src/sio_um8669f.c
@@ -53,6 +53,7 @@ typedef struct um8669f_t
         } dev[8];
 
 	fdc_t *fdc;
+	int pnp_active;
 } um8669f_t;
 
 
@@ -128,7 +129,7 @@ void um8669f_pnp_write(uint16_t port, uint8_t val, void *p)
 				}
                                 break;
                                 case DEV_COM1:
-				if (valxor)
+				if ((um8669f->cur_reg == REG_ENABLE) && valxor)
 				{
 	                                serial_remove(1);
         	                        if (um8669f->dev[DEV_COM1].enable & 1)
@@ -136,7 +137,7 @@ void um8669f_pnp_write(uint16_t port, uint8_t val, void *p)
 				}
                                 break;
                                 case DEV_COM2:
-				if (valxor)
+				if ((um8669f->cur_reg == REG_ENABLE) && valxor)
 				{
 	                                serial_remove(2);
         	                        if (um8669f->dev[DEV_COM2].enable & 1)
@@ -144,7 +145,7 @@ void um8669f_pnp_write(uint16_t port, uint8_t val, void *p)
 				}
                                 break;
                                 case DEV_LPT1:
-				if (valxor)
+				if ((um8669f->cur_reg == REG_ENABLE) && valxor)
 				{
         	                        lpt1_remove();
                 	                if (um8669f->dev[DEV_LPT1].enable & 1)
@@ -186,6 +187,7 @@ uint8_t um8669f_pnp_read(uint16_t port, void *p)
 void um8669f_write(uint16_t port, uint8_t val, void *p)
 {
         um8669f_t *um8669f = (um8669f_t *)p;
+	int new_pnp_active;
 
         if (um8669f->locked)
         {
@@ -206,15 +208,21 @@ void um8669f_write(uint16_t port, uint8_t val, void *p)
 /*                        pclog("Write UM8669f register %02x %02x %04x:%04x %i\n", um8669f_curreg, val, CS,cpu_state.pc, ins); */
                         um8669f->regs_108[um8669f->cur_reg_108] = val;
 
-                        io_removehandler(0x0279, 0x0001, NULL, NULL, NULL, um8669f_pnp_write, NULL, NULL, um8669f);
-                        io_removehandler(0x0a79, 0x0001, NULL, NULL, NULL, um8669f_pnp_write, NULL, NULL, um8669f);
-                        io_removehandler(0x03e3, 0x0001, um8669f_pnp_read, NULL, NULL, NULL, NULL, NULL, um8669f);
-                        if (um8669f->regs_108[0xc1] & 0x80)
-                        {
-                                io_sethandler(0x0279, 0x0001, NULL, NULL, NULL, um8669f_pnp_write, NULL, NULL, um8669f);
-                                io_sethandler(0x0a79, 0x0001, NULL, NULL, NULL, um8669f_pnp_write, NULL, NULL, um8669f);
-                                io_sethandler(0x03e3, 0x0001, um8669f_pnp_read, NULL, NULL, NULL, NULL, NULL, um8669f);
-                        }
+			if (um8669f->cur_reg_108 == 0xc1) {
+				new_pnp_active = !!(um8669f->regs_108[0xc1] & 0x80);
+				if (new_pnp_active != um8669f->pnp_active) {
+        	                	if (new_pnp_active) {
+	        	                        io_sethandler(0x0279, 0x0001, NULL, NULL, NULL, um8669f_pnp_write, NULL, NULL, um8669f);
+        	        	                io_sethandler(0x0a79, 0x0001, NULL, NULL, NULL, um8669f_pnp_write, NULL, NULL, um8669f);
+                	        	        io_sethandler(0x03e3, 0x0001, um8669f_pnp_read, NULL, NULL, NULL, NULL, NULL, um8669f);
+	                	        } else {
+        			                io_removehandler(0x0279, 0x0001, NULL, NULL, NULL, um8669f_pnp_write, NULL, NULL, um8669f);
+        	        		        io_removehandler(0x0a79, 0x0001, NULL, NULL, NULL, um8669f_pnp_write, NULL, NULL, um8669f);
+		                	        io_removehandler(0x03e3, 0x0001, um8669f_pnp_read, NULL, NULL, NULL, NULL, NULL, um8669f);
+					}
+					um8669f->pnp_active = new_pnp_active;
+				}
+			}
                 }
         }
 }
@@ -252,16 +260,19 @@ void um8669f_reset(void)
 	lpt1_remove();
 	lpt1_init(0x378);
         
+	if (um8669f_global.pnp_active) {
+		io_removehandler(0x0279, 0x0001, NULL, NULL, NULL, um8669f_pnp_write, NULL, NULL, &um8669f_global);
+		io_removehandler(0x0a79, 0x0001, NULL, NULL, NULL, um8669f_pnp_write, NULL, NULL, &um8669f_global);
+		io_removehandler(0x03e3, 0x0001, um8669f_pnp_read, NULL, NULL, NULL, NULL, NULL, &um8669f_global);
+		um8669f_global.pnp_active = 0;
+	}
+
         memset(&um8669f_global, 0, sizeof(um8669f_t));
 
 	um8669f_global.fdc = temp_fdc;
 
         um8669f_global.locked = 1;
 
-	io_removehandler(0x0279, 0x0001, NULL, NULL, NULL, um8669f_pnp_write, NULL, NULL, &um8669f_global);
-	io_removehandler(0x0a79, 0x0001, NULL, NULL, NULL, um8669f_pnp_write, NULL, NULL, &um8669f_global);
-	io_removehandler(0x03e3, 0x0001, um8669f_pnp_read, NULL, NULL, NULL, NULL, NULL, &um8669f_global);
-
 	um8669f_global.dev[DEV_FDC].enable = 1;
 	um8669f_global.dev[DEV_FDC].addr = 0x03f0;
 	um8669f_global.dev[DEV_FDC].irq = 6;
diff --git a/src/sound/snd_sb_dsp.c b/src/sound/snd_sb_dsp.c
index f4d354003..66e1c8aca 100644
--- a/src/sound/snd_sb_dsp.c
+++ b/src/sound/snd_sb_dsp.c
@@ -772,11 +772,12 @@ void sb_dsp_init(sb_dsp_t *dsp, int type)
 void sb_dsp_setaddr(sb_dsp_t *dsp, uint16_t addr)
 {
 //        pclog("sb_dsp_setaddr : %04X\n", addr);
-        io_removehandler(dsp->sb_addr + 6,   0x0002, sb_read, NULL, NULL, sb_write, NULL, NULL, dsp);
-        io_removehandler(dsp->sb_addr + 0xa, 0x0006, sb_read, NULL, NULL, sb_write, NULL, NULL, dsp);        
+        if (dsp->sb_addr != 0) {
+	        io_removehandler(dsp->sb_addr + 6,   0x0002, sb_read, NULL, NULL, sb_write, NULL, NULL, dsp);
+        	io_removehandler(dsp->sb_addr + 0xa, 0x0006, sb_read, NULL, NULL, sb_write, NULL, NULL, dsp);        
+	}
         dsp->sb_addr = addr;
-        if (dsp->sb_addr != 0)
-        {
+        if (dsp->sb_addr != 0) {
                 io_sethandler(dsp->sb_addr + 6,   0x0002, sb_read, NULL, NULL, sb_write, NULL, NULL, dsp);
                 io_sethandler(dsp->sb_addr + 0xa, 0x0006, sb_read, NULL, NULL, sb_write, NULL, NULL, dsp);        
         }
diff --git a/src/win/win_cdrom_ioctl.c b/src/win/win_cdrom_ioctl.c
index 5ca208261..48a4c60e6 100644
--- a/src/win/win_cdrom_ioctl.c
+++ b/src/win/win_cdrom_ioctl.c
@@ -9,7 +9,7 @@
  *		Implementation of the CD-ROM host drive IOCTL interface for
  *		Windows using SCSI Passthrough Direct.
  *
- * Version:	@(#)cdrom_ioctl.c	1.0.9	2018/01/17
+ * Version:	@(#)cdrom_ioctl.c	1.0.10	2018/02/01
  *
  * Authors:	Sarah Walker, <http://pcem-emulator.co.uk/>
  *		Miran Grca, <mgrca8@gmail.com>
@@ -51,6 +51,7 @@ typedef struct {
 
 
 cdrom_ioctl_windows_t cdrom_ioctl_windows[CDROM_NUM];
+
 #ifdef ENABLE_CDROM_LOG
 int cdrom_ioctl_do_log = ENABLE_CDROM_LOG;
 #endif
@@ -671,9 +672,9 @@ static int ioctl_get_block_length(uint8_t id, const UCHAR *cdb, int number_of_bl
 			case 0x51:	/* READ DISC INFORMATION */
 			case 0x52:	/* READ TRACK INFORMATION */
 			case 0x5A:	/* MODE SENSE (10) */
-				return ((uint16_t) cdb[8]) + (((uint16_t) cdb[7]) << 8);
+				return (((uint32_t) cdb[7]) << 8) | ((uint32_t) cdb[8]);
 			case 0xAD:	/* READ DVD STRUCTURE */
-				return (((uint32_t) cdb[6]) << 24) | (((uint32_t) cdb[7]) << 16) | (((uint32_t) cdb[8]) << 8) | ((uint32_t) cdb[9]);
+				return (((uint32_t) cdb[8]) << 8) | ((uint32_t) cdb[9]);
 			default:
 				return 65534;
 		}
@@ -689,9 +690,9 @@ static int ioctl_get_block_length(uint8_t id, const UCHAR *cdb, int number_of_bl
 		case 0x51:	/* READ DISC INFORMATION */
 		case 0x52:	/* READ TRACK INFORMATION */
 		case 0x5A:	/* MODE SENSE (10) */
-			return ((uint16_t) cdb[8]) + (((uint16_t) cdb[7]) << 8);
-			case 0xAD:	/* READ DVD STRUCTURE */
-				return (((uint32_t) cdb[6]) << 24) | (((uint32_t) cdb[7]) << 16) | (((uint32_t) cdb[8]) << 8) | ((uint32_t) cdb[9]);
+			return (((uint32_t) cdb[7]) << 8) | ((uint32_t) cdb[8]);
+		case 0xAD:	/* READ DVD STRUCTURE */
+			return (((uint32_t) cdb[8]) << 8) | ((uint32_t) cdb[9]);
 		case 0x08:
 		case 0x28:
 		case 0xa8: