diff --git a/filer.cpp b/filer.cpp
index 80a7f75..4891ec8 100644
--- a/filer.cpp
+++ b/filer.cpp
@@ -22,17 +22,14 @@ static File file;
 static Dir dir;
 #endif
 
-static const char *programs;
-
 #define STORAGE defined(USE_SD) || defined(USE_SPIFFS) || defined(USE_FS)
 
-bool flash_filer::start(const char *programs)
+bool flash_filer::start()
 {
-	::programs = programs;
 #if defined(USE_FS)
-	dir = SPIFFS.openDir(programs);
+	dir = SPIFFS.openDir(_programs);
 #elif defined(DISK)
-	dir = DISK.open(programs);
+	dir = DISK.open(_programs);
 	if (!dir)
 		return false;
 #endif
@@ -72,7 +69,7 @@ const char *flash_filer::advance() {
 			file = dir.openFile("r");
 			break;
 		}
-		dir = SPIFFS.openDir(programs);
+		dir = SPIFFS.openDir(_programs);
 	}
 	strncpy(buf, dir.fileName().c_str(), sizeof(buf));
 	return buf;
@@ -112,7 +109,7 @@ static int cpid = 0;
 const char *flash_filer::checkpoint() {
 #if defined(USE_SD) || defined(USE_SPIFFS) || defined(ESP8266)
 	stop();
-	snprintf(buf, sizeof(buf), "%s%s.%03d", ::programs, chkpt, cpid++);
+	snprintf(buf, sizeof(buf), "%s%s.%03d", _programs, chkpt, cpid++);
 
 #if defined(USE_SD)
 	File file = SD.open(buf, O_WRITE | O_CREAT | O_TRUNC);
@@ -123,7 +120,7 @@ const char *flash_filer::checkpoint() {
 #endif
 	hardware_checkpoint(file);
 	file.close();
-	start(::programs);
+	start();
 #endif
 	return buf;
 }
@@ -131,7 +128,7 @@ const char *flash_filer::checkpoint() {
 void flash_filer::restore(const char *filename) {
 #if defined(USE_SD) || defined(USE_SPIFFS) || defined(ESP8266)
 	stop();
-	snprintf(buf, sizeof(buf), "%s%s", ::programs, filename);
+	snprintf(buf, sizeof(buf), "%s%s", _programs, filename);
 
 #if defined(USE_SD)
 	File file = SD.open(buf, O_READ);
@@ -142,9 +139,9 @@ void flash_filer::restore(const char *filename) {
 #endif
 	hardware_restore(file);
 	file.close();
-	int n = sscanf(buf + strlen(::programs), "%[A-Z0-9].%d", chkpt, &cpid);
+	int n = sscanf(buf + strlen(_programs), "%[A-Z0-9].%d", chkpt, &cpid);
 	cpid = (n == 1)? 0: cpid+1;
 #endif
-	start(::programs);
+	start();
 }
 #endif
diff --git a/filer.h b/filer.h
index a300efa..53de1e8 100644
--- a/filer.h
+++ b/filer.h
@@ -9,7 +9,7 @@ public:
 	virtual const char *checkpoint() =0;
 	virtual void restore(const char *) = 0;
 
-	virtual bool start(const char *) =0;
+	virtual bool start() =0;
 	virtual void stop() =0;
 };
 
@@ -17,19 +17,22 @@ public:
 // implement write to new file (like checkpoint)
 class flash_filer: public filer {
 public:
+	flash_filer(const char *programs): _programs(programs) {}
+
 	const char *advance();
 	const char *rewind();
 
 	const char *checkpoint();
 	void restore(const char *);
 
-	bool start(const char *);
+	bool start();
 	void stop();
 	
 	uint8_t read() { return _buf[_pos++]; }
 	bool more();
 
 private:
+	const char *_programs;
 	unsigned _pos, _len;
 	uint8_t _buf[128];
 };
diff --git a/r65emu.h b/r65emu.h
index 5c641df..0398db3 100644
--- a/r65emu.h
+++ b/r65emu.h
@@ -12,6 +12,7 @@
 #include "serialio.h"
 #include "filer.h"
 #include "serial_filer.h"
+#include "socket_filer.h"
 #include "timed.h"
 #include "hardware.h"
 #include "sound_dac.h"
diff --git a/serial_filer.cpp b/serial_filer.cpp
index a307200..a6a972d 100644
--- a/serial_filer.cpp
+++ b/serial_filer.cpp
@@ -5,10 +5,6 @@
 #include "filer.h"
 #include "serial_filer.h"
 
-bool serial_filer::start(const char *) {
-	return true;
-}
-
 const unsigned speeds[] = {
 	115200, 57600, 19200, 9600, 4800, 2400
 };
@@ -16,7 +12,7 @@ const unsigned speeds[] = {
 const char *serial_filer::advance() {
 	static char buf[16];
 	unsigned s = speeds[_currsp];
-	Serial.begin(s);
+	_serial.begin(s);
 	_currsp++;
 	if (_currsp == sizeof(speeds)/sizeof(speeds[0]))
 		_currsp = 0;
@@ -24,15 +20,15 @@ const char *serial_filer::advance() {
 }
 
 void serial_filer::write(uint8_t b) {
-	Serial.write(b);
+	_serial.write(b);
 }
 
 uint8_t serial_filer::read() {
-	return Serial.read();
+	return _serial.read();
 }
 
 bool serial_filer::more() {
-	return Serial.available() > 0;
+	return _serial.available() > 0;
 }
 
 #if !defined(NO_CHECKPOINT)
diff --git a/serial_filer.h b/serial_filer.h
index 94b3a50..260faa9 100644
--- a/serial_filer.h
+++ b/serial_filer.h
@@ -1,17 +1,21 @@
 #ifndef __SERIAL_FILER_H__
 #define __SERIAL_FILER_H__
 
+class HardwareSerial;
+
 // see https://playground.arduino.cc/Interfacing/LinuxTTY
 // FIXME: do this in minicom config file
 class serial_filer: public filer {
 public:
+	serial_filer(HardwareSerial &serial): _serial(serial) {}
+
 	const char *advance();
 	const char *rewind() { _currsp = 0; return advance(); }
 
 	const char *checkpoint();
 	void restore(const char *);
 
-	bool start(const char *);
+	bool start() { return true; }
 	void stop() {}
 
 	uint8_t read();
@@ -19,6 +23,7 @@ public:
 	void write(uint8_t);
 
 private:
+	HardwareSerial &_serial;
 	unsigned _currsp;
 };
 #endif
diff --git a/socket_filer.cpp b/socket_filer.cpp
index 5e00e81..d23a62b 100644
--- a/socket_filer.cpp
+++ b/socket_filer.cpp
@@ -7,7 +7,7 @@
 
 #if !defined(ESP32)
 #pragma message "no socket filer"
-#else
+#elif defined(WIFI_SSID)
 #include <WiFi.h>
 
 static WiFiServer server(23);
@@ -20,11 +20,11 @@ static bool connected() {
 	return client.connected();
 }
 
-// FIXME: hostname
-bool socket_filer::start(const char *) {
+bool socket_filer::start() {
 
 #if defined(WIFI_SSID)
 	WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
+	WiFi.setHostname(_hostname);
 
 	for (int i=0; i < 60 && WiFi.status() != WL_CONNECTED; i++)
 		delay(1000);
diff --git a/socket_filer.h b/socket_filer.h
index 64b442b..1a3048c 100644
--- a/socket_filer.h
+++ b/socket_filer.h
@@ -3,17 +3,22 @@
 
 class socket_filer: public filer {
 public:
+	socket_filer(const char *hostname): _hostname(hostname) {}
+
 	const char *advance() { return 0; }
 	const char *rewind() { return advance(); }
 
 	const char *checkpoint();
 	void restore(const char *);
 
-	bool start(const char *);
+	bool start();
 	void stop() {}
 
 	uint8_t read();
 	bool more();
 	void write(uint8_t);
+
+private:
+	const char *_hostname;
 };
 #endif