diff --git a/src/codegen_new/codegen_ir_defs.h b/src/codegen_new/codegen_ir_defs.h
index 75d20806d..30bf44d98 100644
--- a/src/codegen_new/codegen_ir_defs.h
+++ b/src/codegen_new/codegen_ir_defs.h
@@ -9,7 +9,7 @@
   All registers must have been written back or discarded.
   This should be used when calling external functions that may change any emulated
   registers.*/
-#define UOP_TYPE_BARRIER (1 << 31)
+#define UOP_TYPE_BARRIER (1u << 31)
 
 /*uOP is a barrier. All previous uOPs must have completed before this one executes.
   All registers must have been written back, but do not have to be discarded.
diff --git a/src/include/86box/network.h b/src/include/86box/network.h
index df04343ca..8e23e671f 100644
--- a/src/include/86box/network.h
+++ b/src/include/86box/network.h
@@ -106,9 +106,6 @@ extern netdev_t network_devs[32];
 
 /* Function prototypes. */
 extern void	network_wait(uint8_t wait);
-extern void	network_poll(void);
-extern void	network_busy(uint8_t set);
-extern void	network_end(void);
 
 extern void	network_init(void);
 extern void	network_attach(void *, uint8_t *, NETRXCB, NETWAITCB, NETSETLINKSTATE);
@@ -116,7 +113,6 @@ extern void	network_close(void);
 extern void	network_reset(void);
 extern int	network_available(void);
 extern void	network_tx(uint8_t *, int);
-extern void	network_do_tx(void);
 extern int	network_tx_queue_check(void);
 
 extern int	net_pcap_prepare(netdev_t *);
diff --git a/src/network/net_pcap.c b/src/network/net_pcap.c
index f40161ff9..52573907b 100644
--- a/src/network/net_pcap.c
+++ b/src/network/net_pcap.c
@@ -180,11 +180,6 @@ poll_thread(void *arg)
 	/* Request ownership of the device. */
 	network_wait(1);
 
-#if 0
-	/* Wait for a poll request. */
-	network_poll();
-#endif
-
 	if (pcap == NULL) {
 		network_wait(0);
 		break;
@@ -211,12 +206,9 @@ poll_thread(void *arg)
 		}
 	}
 
-	/* Wait for the next packet to arrive. */
+	/* Wait for the next packet to arrive - network_do_tx() is called from there. */
 	tx = network_tx_queue_check();
 
-	if (tx)
-		network_do_tx();
-
 	/* Release ownership of the device. */
 	network_wait(0);
 
@@ -346,8 +338,6 @@ net_pcap_close(void)
 
     /* Tell the thread to terminate. */
     if (poll_tid != NULL) {
-	network_busy(0);
-
 	/* Wait for the thread to finish. */
 	pcap_log("PCAP: waiting for thread to end...\n");
 	thread_wait_event(poll_state, -1);
diff --git a/src/network/net_slirp.c b/src/network/net_slirp.c
index aeb28ad37..fc4afcf78 100644
--- a/src/network/net_slirp.c
+++ b/src/network/net_slirp.c
@@ -362,11 +362,6 @@ poll_thread(void *arg)
 	/* Request ownership of the queue. */
 	network_wait(1);
 
-#if 0
-	/* Wait for a poll request. */
-	network_poll();
-#endif
-
 	/* Stop processing if asked to. */
 	if (slirp->stop) {
 		network_wait(0);
@@ -376,12 +371,9 @@ poll_thread(void *arg)
 	/* See if there is any work. */
 	slirp_tic(slirp);
 
-	/* Wait for the next packet to arrive. */
+	/* Wait for the next packet to arrive - network_do_tx() is called from there. */
 	tx = network_tx_queue_check();
 
-	if (tx)
-		network_do_tx();
-
 	/* Release ownership of the queue. */
 	network_wait(0);
 
@@ -454,8 +446,6 @@ net_slirp_close(void)
 
     /* Tell the thread to terminate. */
     if (slirp->poll_tid) {
-	network_busy(0);
-
 	/* Wait for the thread to finish. */
 	slirp_log("SLiRP: waiting for thread to end...\n");
 	thread_wait_event(slirp->poll_state, -1);
diff --git a/src/network/network.c b/src/network/network.c
index acbc30843..8caf11067 100644
--- a/src/network/network.c
+++ b/src/network/network.c
@@ -120,18 +120,9 @@ static mutex_t		*network_mutex;
 static uint8_t		*network_mac;
 static uint8_t		network_timer_active = 0;
 static pc_timer_t	network_rx_queue_timer;
-static netpkt_t		*first_pkt[2] = { NULL, NULL },
-			*last_pkt[2] = { NULL, NULL };
-
-
-static struct {
-    volatile int	busy,
-			queue_in_use;
-
-    event_t		*wake_poll_thread,
-			*poll_complete,
-			*queue_not_in_use;
-} poll_data;
+static netpkt_t		*first_pkt[3] = { NULL, NULL, NULL },
+			*last_pkt[3] = { NULL, NULL, NULL };
+static netpkt_t		queued_pkt;
 
 
 #ifdef ENABLE_NETWORK_LOG
@@ -201,37 +192,6 @@ network_wait(uint8_t wait)
 }
 
 
-void
-network_poll(void)
-{
-    network_wait(0);
-
-    while (poll_data.busy)
-	thread_wait_event(poll_data.wake_poll_thread, -1);
-
-    network_wait(1);
-
-    thread_reset_event(poll_data.wake_poll_thread);
-}
-
-
-void
-network_busy(uint8_t set)
-{
-    poll_data.busy = !!set;
-
-    if (! set)
-	thread_set_event(poll_data.wake_poll_thread);
-}
-
-
-void
-network_end(void)
-{
-    thread_set_event(poll_data.poll_complete);
-}
-
-
 /*
  * Initialize the configured network cards.
  *
@@ -284,8 +244,7 @@ network_queue_put(int tx, void *priv, uint8_t *data, int len)
 {
     netpkt_t *temp;
 
-    temp = (netpkt_t *) malloc(sizeof(netpkt_t));
-    memset(temp, 0, sizeof(netpkt_t));
+    temp = (netpkt_t *) calloc(sizeof(netpkt_t), 1);
     temp->priv = priv;
     memcpy(temp->data, data, len);
     temp->len = len;
@@ -302,17 +261,29 @@ network_queue_put(int tx, void *priv, uint8_t *data, int len)
 
 
 static void
-network_queue_get(int tx, netpkt_t **pkt)
+network_queue_get(int tx, netpkt_t *pkt)
 {
+    netpkt_t *temp;
+
+    temp = first_pkt[tx];
+
+    if (temp == NULL) {
+	memset(pkt, 0x00, sizeof(netpkt_t));
+	return;
+    }
+
+    memcpy(pkt, temp, sizeof(netpkt_t));
+
+    first_pkt[tx] = temp->next;
+    free(temp);
+
     if (first_pkt[tx] == NULL)
-	*pkt = NULL;
-    else
-	*pkt = first_pkt[tx];
+	last_pkt[tx] = NULL;
 }
 
 
 static void
-network_queue_advance(int tx)
+network_queue_transmit(int tx)
 {
     netpkt_t *temp;
 
@@ -321,6 +292,20 @@ network_queue_advance(int tx)
     if (temp == NULL)
 	return;
 
+    if (temp->len > 0) {
+	network_dump_packet(temp);
+	/* Why on earth is this not a function pointer?! */
+	switch(network_type) {
+		case NET_TYPE_PCAP:
+			net_pcap_in(temp->data, temp->len);
+			break;
+
+		case NET_TYPE_SLIRP:
+			net_slirp_in(temp->data, temp->len);
+			break;
+	}
+    }
+
     first_pkt[tx] = temp->next;
     free(temp);
 
@@ -329,6 +314,38 @@ network_queue_advance(int tx)
 }
 
 
+static void
+network_queue_copy(int dest, int src)
+{
+    netpkt_t *temp, *temp2;
+
+    temp = first_pkt[src];
+
+    if (temp == NULL)
+	return;
+
+    temp2 = (netpkt_t *) calloc(sizeof(netpkt_t), 1);
+    temp2->priv = temp->priv;
+    memcpy(temp2->data, temp->data, temp->len);
+    temp2->len = temp->len;
+    temp2->prev = last_pkt[dest];
+    temp2->next = NULL;
+
+    if (last_pkt[dest] != NULL)
+	last_pkt[dest]->next = temp2;
+    last_pkt[dest] = temp2;
+
+    if (first_pkt[dest] == NULL)
+	first_pkt[dest] = temp2;
+
+    first_pkt[src] = temp->next;
+    free(temp);
+
+    if (first_pkt[src] == NULL)
+	last_pkt[src] = NULL;
+}
+
+
 static void
 network_queue_clear(int tx)
 {
@@ -352,29 +369,23 @@ network_rx_queue(void *priv)
 {
     int ret = 1;
 
-    netpkt_t *pkt = NULL;
-
     if (network_rx_pause || !thread_test_mutex(network_mutex)) {
 	timer_on_auto(&network_rx_queue_timer, 0.762939453125 * 2.0 * 128.0);
 	return;
     }
 
-    network_busy(1);
-
-    network_queue_get(0, &pkt);
-    if ((pkt != NULL) && (pkt->len > 0)) {
-	network_dump_packet(pkt);
-	ret = net_cards[network_card].rx(pkt->priv, pkt->data, pkt->len);
-	if (pkt->len >= 128)
-		timer_on_auto(&network_rx_queue_timer, 0.762939453125 * 2.0 * ((double) pkt->len));
-	else
-		timer_on_auto(&network_rx_queue_timer, 0.762939453125 * 2.0 * 128.0);
-    } else
-	timer_on_auto(&network_rx_queue_timer, 0.762939453125 * 2.0 * 128.0);
+    if (queued_pkt.len == 0)
+	network_queue_get(0, &queued_pkt);
+    if (queued_pkt.len > 0) {
+	network_dump_packet(&queued_pkt);
+	ret = net_cards[network_card].rx(queued_pkt.priv, queued_pkt.data, queued_pkt.len);
+    }
+    timer_on_auto(&network_rx_queue_timer, 0.762939453125 * 2.0 * ((queued_pkt.len >= 128) ? ((double) queued_pkt.len) : 128.0));
     if (ret)
-	network_queue_advance(0);
+	queued_pkt.len = 0;
 
-    network_busy(0);
+    /* Transmission. */
+    network_queue_copy(1, 2);
 
     network_wait(0);
 }
@@ -401,10 +412,6 @@ network_attach(void *dev, uint8_t *mac, NETRXCB rx, NETWAITCB wait, NETSETLINKST
 
     network_set_wait(0);
 
-    /* Create the network events. */
-    poll_data.poll_complete = thread_create_event();
-    poll_data.wake_poll_thread = thread_create_event();
-
     /* Activate the platform module. */
     switch(network_type) {
 	case NET_TYPE_PCAP:
@@ -416,8 +423,9 @@ network_attach(void *dev, uint8_t *mac, NETRXCB rx, NETWAITCB wait, NETSETLINKST
 		break;
     }
 
-    first_pkt[0] = first_pkt[1] = NULL;
-    last_pkt[0] = last_pkt[1] = NULL;
+    first_pkt[0] = first_pkt[1] = first_pkt[2] = NULL;
+    last_pkt[0] = last_pkt[1] = last_pkt[2] = NULL;
+    memset(&queued_pkt, 0x00, sizeof(netpkt_t));
     memset(&network_rx_queue_timer, 0x00, sizeof(pc_timer_t));
     timer_add(&network_rx_queue_timer, network_rx_queue, NULL, 0);
     /* 10 mbps. */
@@ -453,16 +461,6 @@ network_close(void)
     /* Force-close the SLIRP module. */
     net_slirp_close();
 
-    /* Close the network events. */
-    if (poll_data.wake_poll_thread != NULL) {
-	thread_destroy_event(poll_data.wake_poll_thread);
-	poll_data.wake_poll_thread = NULL;
-    }
-    if (poll_data.poll_complete != NULL) {
-	thread_destroy_event(poll_data.poll_complete);
-	poll_data.poll_complete = NULL;
-    }
-
     /* Close the network thread mutex. */
     thread_close_mutex(network_mutex);
     network_mutex = NULL;
@@ -551,50 +549,25 @@ network_reset(void)
 void
 network_tx(uint8_t *bufp, int len)
 {
-    network_busy(1);
-
     ui_sb_update_icon(SB_NETWORK, 1);
 
-    network_queue_put(1, NULL, bufp, len);
+    network_queue_put(2, NULL, bufp, len);
 
     ui_sb_update_icon(SB_NETWORK, 0);
-
-    network_busy(0);
 }
 
 
 /* Actually transmit the packet. */
-void
-network_do_tx(void)
-{
-    netpkt_t *pkt = NULL;
-
-    if (network_tx_pause)
-	return;
-
-    network_queue_get(1, &pkt);
-    if ((pkt != NULL) && (pkt->len > 0)) {
-	network_dump_packet(pkt);
-	switch(network_type) {
-		case NET_TYPE_PCAP:
-			net_pcap_in(pkt->data, pkt->len);
-			break;
-
-		case NET_TYPE_SLIRP:
-			net_slirp_in(pkt->data, pkt->len);
-			break;
-	}
-    }
-    network_queue_advance(1);
-}
-
-
 int
 network_tx_queue_check(void)
 {
     if ((first_pkt[1] == NULL) && (last_pkt[1] == NULL))
 	return 0;
 
+    if (network_tx_pause)
+	return 1;
+
+    network_queue_transmit(1);
     return 1;
 }
 
diff --git a/src/pic.c b/src/pic.c
index 899029c14..efe81f470 100644
--- a/src/pic.c
+++ b/src/pic.c
@@ -222,7 +222,7 @@ find_best_interrupt(pic_t *dev)
 	if (dev == &pic2)
 		intr += 8;
 
-	if (cpu_fast_off_flags & (1 << intr))
+	if (cpu_fast_off_flags & (1u << intr))
 		cpu_fast_off_count = cpu_fast_off_val + 1;
     }
 
diff --git a/src/qt/qt_main.cpp b/src/qt/qt_main.cpp
index 9d4c57d19..46cf9a5dd 100644
--- a/src/qt/qt_main.cpp
+++ b/src/qt/qt_main.cpp
@@ -114,7 +114,7 @@ main_thread_fn()
             }
         } else {
             /* Just so we dont overload the host OS. */
-            if (drawits < -1)
+            if (drawits < -1 || dopause)
                 std::this_thread::sleep_for(std::chrono::milliseconds(1));
             else
                 std::this_thread::yield();
diff --git a/src/video/vid_svga.c b/src/video/vid_svga.c
index 74bc45910..22fc22f48 100644
--- a/src/video/vid_svga.c
+++ b/src/video/vid_svga.c
@@ -936,11 +936,11 @@ svga_init(const device_t *info, svga_t *svga, void *p, int memsize,
     svga->dispontime = 1000ull << 32;
     svga->dispofftime = 1000ull << 32;
     svga->bpp = 8;
-    svga->vram = malloc(memsize);
+    svga->vram = calloc(memsize, 1);
     svga->vram_max = memsize;
     svga->vram_display_mask = svga->vram_mask = memsize - 1;
     svga->decode_mask = 0x7fffff;
-    svga->changedvram = malloc(memsize >> 12);
+    svga->changedvram = calloc(memsize >> 12, 1);
     svga->recalctimings_ex = recalctimings_ex;
     svga->video_in  = video_in;
     svga->video_out = video_out;