diff --git a/bus.cpp b/bus.cpp
index d0f3cfa..c051c59 100644
--- a/bus.cpp
+++ b/bus.cpp
@@ -297,6 +297,8 @@ uint16_t bus::read(const uint16_t a, const bool word_mode, const bool use_prev)
 
 	if (a < 01000)
 		run_mode = 0;
+	else if (use_prev)
+		run_mode = (c->getPSW() >> 12) & 3;
 
 	uint32_t m_offset = pages[run_mode][apf].par * 64;
 
@@ -556,6 +558,8 @@ uint16_t bus::write(const uint16_t a, const bool word_mode, uint16_t value, cons
 
 	if (a < 01000)
 		run_mode = 0;
+	else if (use_prev)
+		run_mode = (c->getPSW() >> 12) & 3;
 
 	uint32_t m_offset = pages[run_mode][apf].par * 64;
 
diff --git a/cpu.cpp b/cpu.cpp
index ad6efe4..a478fbe 100644
--- a/cpu.cpp
+++ b/cpu.cpp
@@ -857,20 +857,22 @@ bool cpu::single_operand_instructions(const uint16_t instr)
 				 }
 
 		case 0b00110101: { // MFPD/MFPI
-					 // FIXME
-					 uint16_t v = getGAM(dst_mode, dst_reg, word_mode, true);
+					 // for MFPD versus MFPI
+					 uint16_t a = getGAMAddress(dst_mode, dst_reg, false, false);
+					 uint16_t v = b -> read(a, false, true);
+
 					 setPSW_n(word_mode ? v & 0x80 : v & 0x8000);
 					 setPSW_z(v == 0);
 					 setPSW_v(false);
+
 					 pushStack(v);
+
 					 break;
 				 }
 
 		case 0b00110110: { // MTPI/MTPD
 					 // always words: word_mode-bit is to select between MTPI and MTPD
 
-					 // calculate address in '13/12'-address-space
-					 uint16_t a = getGAMAddress(dst_mode, dst_reg, false, true);
 					 // retrieve word from '15/14'-stack
 					 uint16_t v = popStack();
 
@@ -878,12 +880,14 @@ bool cpu::single_operand_instructions(const uint16_t instr)
 					 setPSW_z(v == 0);
 					 setPSW_v(false);
 
-					 D(fprintf(stderr, "MTP%c: address %06o, value %06o\n", word_mode ? 'D' : 'I', a, v);)
-
 					 if (dst_mode == 0)
-						 putGAM(dst_mode, dst_reg, false, v, false); // ???
-					 else
-						 b -> write(a, false, v);
+						 putGAM(dst_mode, dst_reg, false, v, true);
+					 else {
+						 uint16_t a = getGAMAddress(dst_mode, dst_reg, false, false);
+
+						 // put in '13/12' address space
+						 b -> write(a, false, v, true);
+					 }
 
 					 break;
 				 }