diff --git a/httpd/httpd.c b/httpd/httpd.c
index 411ba0c..45fdfb2 100644
--- a/httpd/httpd.c
+++ b/httpd/httpd.c
@@ -553,7 +553,7 @@ void handle_post(void)
 			session_id[SESSION_ID_LENGTH] = NUL;
 			slen = strtox(outbuf, "HTTP/1.1 302 Found\r\nConnection: close\r\nLocation: index.html\r\n" \
 					      "Set-Cookie: session=");
-			for (register uint8_t i = 0; i < SESSION_ID_LENGTH; i++)
+			for (uint8_t i = 0; i < SESSION_ID_LENGTH; i++)
 				outbuf[slen++] = session_id[i];
 			slen += strtox(outbuf + slen, "; SameSite=Strict\r\n\r\n");
 		} else {
diff --git a/httpd/page_impl.c b/httpd/page_impl.c
index d55d4fe..2f94568 100644
--- a/httpd/page_impl.c
+++ b/httpd/page_impl.c
@@ -157,14 +157,14 @@ void sfr_data_to_html(void)
 }
 
 
-void reg_to_html(register uint16_t reg)
+void reg_to_html(uint16_t reg)
 {
 	reg_read_m(reg);
 	sfr_data_to_html();
 }
 
 
-void reg_to_html_long(register uint16_t reg)
+void reg_to_html_long(uint16_t reg)
 {
 	reg_read_m(reg);
 	byte_to_html(sfr_data[0]);
@@ -697,13 +697,13 @@ void send_status(void)
 					sfp_send_data(sfp, 238, 1);
 				}
 				slen += strtox(outbuf + slen,"\",\"sfp_vendor\":\"");
-				for (register uint8_t s = 0; s < 16 && sfp_module_vendor[sfp][s]; s++)
+				for (uint8_t s = 0; s < 16 && sfp_module_vendor[sfp][s]; s++)
 					outbuf[slen++] = sfp_module_vendor[sfp][s];
 				slen += strtox(outbuf + slen,"\",\"sfp_model\":\"");
-				for (register uint8_t s = 0; s < 16 && sfp_module_model[sfp][s]; s++)
+				for (uint8_t s = 0; s < 16 && sfp_module_model[sfp][s]; s++)
 					outbuf[slen++] = sfp_module_model[sfp][s];
 				slen += strtox(outbuf + slen,"\",\"sfp_serial\":\"");
-				for (register uint8_t s = 0; s < 16 && sfp_module_serial[sfp][s]; s++)
+				for (uint8_t s = 0; s < 16 && sfp_module_serial[sfp][s]; s++)
 					outbuf[slen++] = sfp_module_serial[sfp][s];
 				slen += strtox(outbuf + slen,"\",\"sfp_los\":");
 				if (machine.sfp_port[sfp].pin_los == GPIO_NA) {
diff --git a/installer/installer.c b/installer/installer.c
index 675a142..f86b782 100644
--- a/installer/installer.c
+++ b/installer/installer.c
@@ -213,7 +213,7 @@ uint8_t flash_read_status(void)
  * Reads bulk data of length len from the flash memory starging at address src
  * and writes the data into a buffer pointed to by dst in XMEM
  */
-void flash_read_bulk(register __xdata uint8_t *dst, __xdata uint32_t src, register uint16_t len)
+void flash_read_bulk(__xdata uint8_t *dst, __xdata uint32_t src, uint16_t len)
 {
 	short status;
 	do {
diff --git a/rtl837x_common.h b/rtl837x_common.h
index 432260e..c3d83cb 100644
--- a/rtl837x_common.h
+++ b/rtl837x_common.h
@@ -161,13 +161,13 @@ void sfr_mask_data(uint8_t n, uint8_t mask, uint8_t set);
 void sfr_set_zero(void);
 void reset_chip(void);
 void memcpy(__xdata void * __xdata dst, __xdata const void * __xdata src, uint16_t len);
-void memcpyc(register __xdata uint8_t *dst, register __code uint8_t *src, register uint16_t len);
-void memset(register __xdata uint8_t *dst, register __xdata uint8_t v, register uint8_t len);
-uint16_t strlen(register __code const char *s);
-uint16_t strlen_x(register __xdata const char *s);
-uint16_t strtox(register __xdata uint8_t *dst, register __code const char *s);
-uint16_t strcpy(register __xdata uint8_t *dst, register const char *s);
-char strcmp(register __xdata const uint8_t *a, register __code const uint8_t *b);
+void memcpyc(__xdata uint8_t *dst, __code uint8_t *src, uint16_t len);
+void memset(__xdata uint8_t *dst, __xdata uint8_t v, uint8_t len);
+uint16_t strlen(__code const char *s);
+uint16_t strlen_x(__xdata const char *s);
+uint16_t strtox(__xdata uint8_t *dst, __code const char *s);
+uint16_t strcpy(__xdata uint8_t *dst, const char *s);
+char strcmp(__xdata const uint8_t *a, __code const uint8_t *b);
 bool strstart(__xdata const uint8_t *a, __code const uint8_t *b);
 bool strstart_x(__xdata const uint8_t *a, __xdata const uint8_t *b);
 void tcpip_output(void);
diff --git a/rtl837x_port.c b/rtl837x_port.c
index 103ac4e..808521f 100644
--- a/rtl837x_port.c
+++ b/rtl837x_port.c
@@ -30,7 +30,7 @@ __xdata	uint32_t l2_head;
 
 __xdata struct vlan_settings vlan_settings;
 
-void port_mirror_set(register uint8_t port, __xdata uint16_t rx_pmask, __xdata uint16_t tx_pmask) __banked
+void port_mirror_set(uint8_t port, __xdata uint16_t rx_pmask, __xdata uint16_t tx_pmask) __banked
 {
 	print_string("\nport_mirror_set called \n");
 	print_string("Mirroring port: "); print_byte(port); print_string(" with rx-mask: ");
@@ -162,7 +162,7 @@ void vlan_name_remove(uint16_t vlan) __banked
  * Reads VLAN information from VLAN table
  * Returns data in sfr_data
  */
-int8_t vlan_get(register uint16_t vlan) __banked
+int8_t vlan_get(uint16_t vlan) __banked
 {
 	if (vlan >= 0xfff) // VLAN 4095 is special
 		return -1;
@@ -177,7 +177,7 @@ int8_t vlan_get(register uint16_t vlan) __banked
 }
 
 
-__xdata uint16_t vlan_name(register uint16_t vlan) __banked
+__xdata uint16_t vlan_name(uint16_t vlan) __banked
 {
 	__xdata int16_t i = 0;
 	__xdata uint8_t begin = 1;
@@ -505,14 +505,14 @@ void port_stats_print(void) __banked
 }
 
 
-void port_isolate(register uint8_t port, __xdata uint16_t pmask) __banked
+void port_isolate(uint8_t port, __xdata uint16_t pmask) __banked
 {
 	if (port <= machine.max_port)
 		REG_SET(RTL837X_PORT_ISOLATION_BASE + (port << 2), pmask);
 }
 
 
-uint16_t port_isolation_get(register uint8_t port) __banked
+uint16_t port_isolation_get(uint8_t port) __banked
 {
 	if (port > machine.max_port)
 		return 0;
diff --git a/rtl837x_port.h b/rtl837x_port.h
index b459832..b9bc84a 100644
--- a/rtl837x_port.h
+++ b/rtl837x_port.h
@@ -48,8 +48,8 @@ extern __xdata struct vlan_settings vlan_settings;
 uint8_t port_l2_forget(void) __banked;
 void port_l2_learned(void) __banked;
 void port_stats_print(void) __banked;
-int8_t vlan_get(register uint16_t vlan) __banked;
-__xdata uint16_t vlan_name(register uint16_t vlan) __banked;
+int8_t vlan_get(uint16_t vlan) __banked;
+__xdata uint16_t vlan_name(uint16_t vlan) __banked;
 void vlan_name_remove(uint16_t vlan) __banked;
 void vlan_setup(void) __banked;
 void port_pvid_set(uint8_t port, __xdata uint16_t pvid) __banked;
@@ -57,7 +57,7 @@ uint16_t port_pvid_get(uint8_t port) __banked;
 void vlan_create(void) __banked;
 void vlan_delete(uint16_t vlan) __banked;
 void vlan_dump(void) __banked;
-void port_mirror_set(register uint8_t port, __xdata uint16_t rx_pmask, __xdata uint16_t tx_pmask) __banked;
+void port_mirror_set(uint8_t port, __xdata uint16_t rx_pmask, __xdata uint16_t tx_pmask) __banked;
 void port_mirror_del(void) __banked;
 bool port_ingress_filter(__xdata uint8_t port, __xdata vlan_ingress_mode_t type) __banked;
 void port_l2_setup(void) __banked;
@@ -73,7 +73,7 @@ void port_eee_status(uint8_t port) __banked;
 void print_port_ingress_filter_mode(vlan_ingress_mode_t mode) __banked;
 bool port_ingress_vlan_filter_set(__xdata uint8_t port, __xdata bool enabled) __banked;
 bool port_ingress_vlan_filter_get(__xdata uint8_t port) __banked;
-void port_isolate(register uint8_t port, __xdata uint16_t pmask) __banked;
-uint16_t port_isolation_get(register uint8_t port) __banked;
+void port_isolate(uint8_t port, __xdata uint16_t pmask) __banked;
+uint16_t port_isolation_get(uint8_t port) __banked;
 
 #endif
diff --git a/rtlplayground.c b/rtlplayground.c
index f0a3292..cd5e14e 100644
--- a/rtlplayground.c
+++ b/rtlplayground.c
@@ -311,20 +311,20 @@ void memcpy(__xdata void * __xdata dst, __xdata const void * __xdata src, uint16
 		*d++ = *s++;
 }
 
-void memcpyc(register __xdata uint8_t *dst, register __code uint8_t *src, register uint16_t len)
+void memcpyc(__xdata uint8_t *dst, __code uint8_t *src, uint16_t len)
 {
 	while (len--)
 		*dst++ = *src++;
 }
 
 
-void memset(register __xdata uint8_t *dst, register __xdata uint8_t v, register uint8_t len)
+void memset(__xdata uint8_t *dst, __xdata uint8_t v, uint8_t len)
 {
 	while (len--)
 		*dst++ = v;
 }
 
-uint16_t strtox(register __xdata uint8_t *dst, register __code const char *s)
+uint16_t strtox(__xdata uint8_t *dst, __code const char *s)
 {
 	__xdata uint8_t *b = dst;
 	while (*s)
@@ -334,7 +334,7 @@ uint16_t strtox(register __xdata uint8_t *dst, register __code const char *s)
 }
 
 
-uint16_t strlen(register __code const char *s)
+uint16_t strlen(__code const char *s)
 {
 	uint16_t l = 0;
 	while (s[l])
@@ -343,7 +343,7 @@ uint16_t strlen(register __code const char *s)
 }
 
 
-uint16_t strlen_x(register __xdata const char *s)
+uint16_t strlen_x(__xdata const char *s)
 {
 	uint16_t l = 0;
 	while (s[l])
@@ -352,7 +352,7 @@ uint16_t strlen_x(register __xdata const char *s)
 }
 
 
-char strcmp(register __xdata const uint8_t *a, register __code const uint8_t *b)
+char strcmp(__xdata const uint8_t *a, __code const uint8_t *b)
 {
 	uint8_t i = 0;
 
@@ -667,7 +667,7 @@ void nic_rx_header(uint16_t ring_ptr)
  * data will be returned in the xmem buffer points to
  * ring_ptr is the current position of the RX Ring on the ASIC side
  */
-void nic_rx_packet(register uint16_t buffer, register uint16_t ring_ptr)
+void nic_rx_packet(uint16_t buffer, uint16_t ring_ptr)
 {
 	SFR_NIC_DATA_U16LE = buffer;
 	SFR_NIC_RING_U16LE = ring_ptr;
@@ -1220,7 +1220,7 @@ void handle_tx(void)
 }
 
 
-static inline uint8_t sfp_rate_to_sds_config(register uint8_t rate)
+static inline uint8_t sfp_rate_to_sds_config(uint8_t rate)
 {
 	if (rate == 0x1 || rate == 0x2)
 		return SDS_100FX;
diff --git a/uip/psock.c b/uip/psock.c
index eb4d1af..f1c1115 100644
--- a/uip/psock.c
+++ b/uip/psock.c
@@ -75,8 +75,7 @@
 /*---------------------------------------------------------------------------*/
 
 inline void
-buf_setup(register __xdata struct psock_buf *buf,
-	  register __xdata u8_t *bufptr, register u16_t bufsize)
+buf_setup(__xdata struct psock_buf *buf, __xdata u8_t *bufptr, u16_t bufsize)
 {
   buf->ptr = bufptr;
   buf->left = bufsize;
@@ -84,7 +83,7 @@ buf_setup(register __xdata struct psock_buf *buf,
 
 /*---------------------------------------------------------------------------*/
 inline u8_t
-buf_bufdata(register __xdata struct psock_buf *buf, register __xdata u8_t **dataptr, register __xdata u16_t *datalen)
+buf_bufdata(__xdata struct psock_buf *buf, __xdata u8_t **dataptr, __xdata u16_t *datalen)
 {
   if(*datalen < buf->left) {
     memcpy(buf->ptr, *dataptr, *datalen);
@@ -145,7 +144,7 @@ buf_bufto(__xdata struct psock_buf *buf, u8_t endmarker,
 }
 /*---------------------------------------------------------------------------*/
 static char
-send_data(register __xdata struct psock *s)
+send_data(__xdata struct psock *s)
 {
   if(s->state != STATE_DATA_SENT || uip_rexmit()) {
     if(s->sendlen > uip_mss()) {
@@ -160,7 +159,7 @@ send_data(register __xdata struct psock *s)
 }
 /*---------------------------------------------------------------------------*/
 static char
-data_acked(register __xdata struct psock *s)
+data_acked(__xdata struct psock *s)
 {
   if(s->state == STATE_DATA_SENT && uip_acked()) {
     if(s->sendlen > uip_mss()) {
@@ -176,8 +175,7 @@ data_acked(register __xdata struct psock *s)
   return 0;
 }
 /*---------------------------------------------------------------------------*/
-PT_THREAD(psock_send(register __xdata struct psock *s, register __xdata const char *buf,
-		     register uint16_t len))
+PT_THREAD(psock_send(__xdata struct psock *s, __xdata const char *buf, uint16_t len))
 {
   PT_BEGIN(&s->psockpt);
 
@@ -218,7 +216,7 @@ PT_THREAD(psock_send(register __xdata struct psock *s, register __xdata const ch
 
 
 /*---------------------------------------------------------------------------*/
-// PT_THREAD(psock_generator_send(register __xdata struct psock *s,
+// PT_THREAD(psock_generator_send(__xdata struct psock *s,
 // 			       unsigned short (*generate)(void *), void *arg))
 // {
 //   PT_BEGIN(&s->psockpt);
@@ -275,7 +273,7 @@ psock_newdata(__xdata struct psock *s)
   }
 }
 /*---------------------------------------------------------------------------*/
-PT_THREAD(psock_readto(register __xdata struct psock *psock, unsigned char c))
+PT_THREAD(psock_readto(__xdata struct psock *psock, unsigned char c))
 {
   PT_BEGIN(&psock->psockpt);
 
@@ -304,7 +302,7 @@ PT_THREAD(psock_readto(register __xdata struct psock *psock, unsigned char c))
   PT_END(&psock->psockpt);
 }
 /*---------------------------------------------------------------------------*/
-PT_THREAD(psock_readbuf(register __xdata struct psock *psock))
+PT_THREAD(psock_readbuf(__xdata struct psock *psock))
 {
   PT_BEGIN(&psock->psockpt);
 
@@ -334,7 +332,7 @@ PT_THREAD(psock_readbuf(register __xdata struct psock *psock))
 }
 /*---------------------------------------------------------------------------*/
 void
-psock_init(register __xdata struct psock *psock, register __xdata char *buffer, register uint16_t buffersize)
+psock_init(__xdata struct psock *psock, __xdata char *buffer, uint16_t buffersize)
 {
   psock->state = STATE_NONE;
   psock->readlen = 0;
diff --git a/uip/psock.h b/uip/psock.h
index a4967d2..3a6e7e4 100644
--- a/uip/psock.h
+++ b/uip/psock.h
@@ -124,7 +124,7 @@ struct psock {
   u8_t state;                   /* The state of the protosocket. */
 };
 
-void psock_init(__xdata struct psock *psock, register __xdata char *buffer, register uint16_t buffersize);
+void psock_init(__xdata struct psock *psock, __xdata char *buffer, uint16_t buffersize);
 /**
  * Initialize a protosocket.
  *
@@ -158,7 +158,7 @@ void psock_init(__xdata struct psock *psock, register __xdata char *buffer, regi
  */
 #define PSOCK_BEGIN(psock) PT_BEGIN(&((psock)->pt))
 
-PT_THREAD(psock_send(register __xdata struct psock *psock, register __xdata const char *buf, register uint16_t len));
+PT_THREAD(psock_send(__xdata struct psock *psock, __xdata const char *buf, uint16_t len));
 /**
  * Send data.
  *
diff --git a/uip/uip.c b/uip/uip.c
index 6a194c1..27a22be 100644
--- a/uip/uip.c
+++ b/uip/uip.c
@@ -400,7 +400,7 @@ uip_init(void) __banked
 /*---------------------------------------------------------------------------*/
 #if UIP_ACTIVE_OPEN
 __xdata struct uip_conn *
-uip_connect(register __xdata uip_ipaddr_t *ripaddr, __xdata u16_t rport) __banked
+uip_connect(__xdata uip_ipaddr_t *ripaddr, __xdata u16_t rport) __banked
 {
   __xdata struct uip_conn *conn, *cconn;
   
@@ -677,7 +677,7 @@ uip_add_rcv_nxt(u16_t n)
 void
 uip_process(u8_t flag) __banked
 {
-  register __xdata struct uip_conn *uip_connr = uip_conn;
+  __xdata struct uip_conn *uip_connr = uip_conn;
 
 #if UIP_UDP
   if(flag == UIP_UDP_SEND_CONN) {