diff --git a/bus.cpp b/bus.cpp
index d24b3b2..afd6d92 100644
--- a/bus.cpp
+++ b/bus.cpp
@@ -259,7 +259,7 @@ uint16_t bus::read_io(const uint16_t addr_in, const word_mode_t word_mode, const
 		return 0;
 	}
 
-	if (word_mode) {
+	if (word_mode == wm_byte) {
 		if (addr_in == ADDR_PSW) { // PSW
 			uint8_t temp = c->getPSW();
 			if (!peek_only) DOLOG(debug, false, "READ-I/O PSW LSB: %03o", temp);
@@ -430,7 +430,7 @@ uint16_t bus::read(const uint16_t addr_in, const word_mode_t word_mode, const rm
 
 	uint16_t temp   = 0;
 
-	if (word_mode)
+	if (word_mode == wm_byte)
 		temp = m->readByte(m_offset);
 	else
 		temp = m->readWord(m_offset);
@@ -702,22 +702,14 @@ void bus::write_pdr(const uint32_t a, const int run_mode, const uint16_t value,
 	bool is_d = a & 16;
 	int  page = (a >> 1) & 7;
 
-	if (word_mode) {
+	if (word_mode == wm_byte) {
 		assert(a != 0 || value < 256);
 
 		a & 1 ? (pages[run_mode][is_d][page].pdr &= 0x00ff, pages[run_mode][is_d][page].pdr |= value << 8) :
-#ifdef SYSTEM_11_44
-			(pages[run_mode][is_d][page].pdr &= 0xff00, pages[run_mode][is_d][page].pdr |= value & ~0361);
-#else
 			(pages[run_mode][is_d][page].pdr &= 0xff00, pages[run_mode][is_d][page].pdr |= value     );
-#endif
 	}
 	else {
-#ifdef SYSTEM_11_44
-		pages[run_mode][is_d][page].pdr = value & ~0361;
-#else
 		pages[run_mode][is_d][page].pdr = value;
-#endif
 	}
 
 	pages[run_mode][is_d][page].pdr &= ~(32768 + 128 /*A*/ + 64 /*W*/ + 32 + 16);  // set bit 4, 5 & 15 to 0 as they are unused and A/W are set to 0 by writes
@@ -730,7 +722,7 @@ void bus::write_par(const uint32_t a, const int run_mode, const uint16_t value,
 	bool is_d = a & 16;
 	int  page = (a >> 1) & 7;
 
-	if (word_mode) {
+	if (word_mode == wm_byte) {
 		a & 1 ? (pages[run_mode][is_d][page].par &= 0x00ff, pages[run_mode][is_d][page].par |= value << 8) :
 			(pages[run_mode][is_d][page].par &= 0xff00, pages[run_mode][is_d][page].par |= value     );
 	}
@@ -747,7 +739,7 @@ void bus::write_io(const uint16_t addr_in, const word_mode_t word_mode, const ui
 {
 	uint16_t value = value_in;
 
-	if (word_mode) {
+	if (word_mode == wm_byte) {
 		if (addr_in == ADDR_PSW || addr_in == ADDR_PSW + 1) { // PSW
 			DOLOG(debug, true, "WRITE-I/O PSW %s: %03o", addr_in & 1 ? "MSB" : "LSB", value);
 
@@ -1034,7 +1026,7 @@ void bus::write(const uint16_t addr_in, const word_mode_t word_mode, uint16_t va
 
 	DOLOG(debug, true, "WRITE to %06o/%07o %c %c: %06o", addr_in, m_offset, space == d_space ? 'D' : 'I', word_mode ? 'B' : 'W', value);
 
-	if (word_mode)
+	if (word_mode == wm_byte)
 		m->writeByte(m_offset, value);
 	else
 		m->writeWord(m_offset, value);