diff --git a/src/calc.c b/src/calc.c
index 9270262..336504e 100644
--- a/src/calc.c
+++ b/src/calc.c
@@ -34,7 +34,8 @@ __xdata dec80 LastX;
 #define STACK_T 3
 
 uint8_t NoLift = 0;
-__bit IsShifted = 0;
+__bit IsShiftedUp = 0;
+__bit IsShiftedDown = 0;
 
 //stack "grows" towards 0
 __xdata dec80 Stack[STACK_SIZE]; //0->x, 1->y, 2->z, 3->t initially
@@ -88,10 +89,6 @@ static void do_unary_op(void (*f_ptr)(void)){
 	}
 }
 
-static void toggle_shifted(void){
-	IsShifted ^= 1;
-}
-
 void process_cmd(char cmd){
 	//turn off backlight before start of processing
 	backlight_off();
@@ -99,12 +96,12 @@ void process_cmd(char cmd){
 	switch(cmd){
 		//////////
 		case '+':{
-			if (IsShifted){ // LastX
+			if (IsShiftedUp){ // LastX
 				if (NoLift != 1){
 					StackPtr--;
 				}
 				copy_decn(&stack(STACK_X), &LastX);
-				IsShifted = 0;
+				IsShiftedUp = 0;
 			} else { // +
 				do_binary_op(add_decn);
 			}
@@ -115,22 +112,36 @@ void process_cmd(char cmd){
 		} break;
 		//////////
 		case '-':{
-			negate_decn(&stack(STACK_X));
-			do_binary_op(add_decn);
-			negate_decn(&LastX); //stored LastX was after negation of X
+			if (IsShiftedUp) {
+				do_unary_op(to_radian_decn);
+				IsShiftedUp = 0;
+			} else if (IsShiftedDown) {
+				do_unary_op(to_degree_decn);
+				IsShiftedDown = 0;
+			} else {
+				negate_decn(&stack(STACK_X));
+				do_binary_op(add_decn);
+				negate_decn(&LastX); //stored LastX was after negation of X
+			}
 		} break;
 		//////////
 		case '/':{
-			do_binary_op(div_decn);
+			if (IsShiftedUp){
+				StackPtr--;
+				pi_decn();
+				copy_decn(&stack(STACK_X), &AccDecn);
+			} else if (IsShiftedDown) {
+			} else {
+				do_binary_op(div_decn);
+			}
 		} break;
 		//////////
 		case '=':{
-			if (IsShifted){ //RCL
+			if (IsShiftedUp){ //RCL
 				if (NoLift != 1){
 					StackPtr--;
 				}
 				copy_decn(&stack(STACK_X), &StoredDecn);
-				IsShifted = 0;
 			} else { //Enter
 				if (!decn_is_nan(&stack(STACK_X))){
 					StackPtr--;
@@ -140,9 +151,8 @@ void process_cmd(char cmd){
 		} break;
 		//////////
 		case '.':{
-			if (IsShifted){ //STO
+			if (IsShiftedUp){ //STO
 				copy_decn(&StoredDecn, &stack(STACK_X));
-				IsShifted = 0;
 			}
 		} break;
 		//////////
@@ -151,8 +161,8 @@ void process_cmd(char cmd){
 		} break;
 		//////////
 		case '<':{ //use as +/- and sqrt
-			if (IsShifted){ //take sqrt
-				IsShifted = 0;
+			if (IsShiftedUp){ //take sqrt
+				IsShiftedUp = 0;
 				if (decn_is_zero(&stack(STACK_X))){
 					//sqrt(0) = 0
 				} else if (!decn_is_nan(&stack(STACK_X))){
@@ -176,8 +186,7 @@ void process_cmd(char cmd){
 		} break;
 		//////////
 		case 'r':{ //use as swap and 1/x
-			if (IsShifted){ //take 1/x
-				IsShifted = 0;
+			if (IsShiftedUp){ //take 1/x
 				do_unary_op(recip_decn);
 			} else { // swap
 				if (!decn_is_nan(&stack(STACK_X))){
@@ -190,41 +199,70 @@ void process_cmd(char cmd){
 		} break;
 		//////////
 		case 'm':{ //use as shift
-			toggle_shifted();
+			if (IsShiftedUp) {
+				IsShiftedUp = 0;
+				IsShiftedDown = 1;
+			} else if (IsShiftedDown) {
+				IsShiftedUp = 0;
+				IsShiftedDown = 0;
+			} else {
+				IsShiftedUp = 1;
+				IsShiftedDown = 0;
+			}
+			return;
+		} break;
+		//////////
+		case '1':{
+			if (IsShiftedUp){
+				do_unary_op(sin_decn);
+			} else if (IsShiftedDown){
+				// do_unary_op(arcsin_decn);
+			}
+		} break;
+		//////////
+		case '2':{
+			if (IsShiftedUp){
+				do_unary_op(cos_decn);
+			} else if (IsShiftedDown){
+				// do_unary_op(arccos_decn);
+			}
+		} break;
+		//////////
+		case '3':{
+			if (IsShiftedUp){
+				do_unary_op(tan_decn);
+			} else if (IsShiftedDown){
+				do_unary_op(arctan_decn);
+			}
 		} break;
 		//////////
 		case '4':{
-			if (IsShifted){ //roll down
+			if (IsShiftedUp){ //roll down
 				StackPtr++;
-				IsShifted = 0;
 			}
 		} break;
 		//////////
 		case '5':{
-			if (IsShifted){ //e^x
+			if (IsShiftedUp){ //e^x
 				do_unary_op(exp_decn);
-				IsShifted = 0;
 			}
 		} break;
 		//////////
 		case '6':{
-			if (IsShifted){ //10^x
+			if (IsShiftedUp){ //10^x
 				do_unary_op(exp10_decn);
-				IsShifted = 0;
 			}
 		} break;
 		//////////
 		case '9':{
-			if (IsShifted){ //log10(x)
+			if (IsShiftedUp){ //log10(x)
 				do_unary_op(log10_decn);
-				IsShifted = 0;
 			}
 		} break;
 		//////////
 		case '8':{
-			if (IsShifted){ //ln(x)
+			if (IsShiftedUp){ //ln(x)
 				do_unary_op(ln_decn);
-				IsShifted = 0;
 			}
 		} break;
 		//////////
@@ -239,10 +277,11 @@ void process_cmd(char cmd){
 				copy_decn(&stack(STACK_Y), &AccDecn);
 			}
 			pop();
-			IsShifted = 0;
 		} break;
 		//////////
 	} //switch(cmd)
+	IsShiftedUp = 0;
+	IsShiftedDown = 0;
 }
 
 
diff --git a/src/calc.h b/src/calc.h
index 2c0c987..ca25d63 100644
--- a/src/calc.h
+++ b/src/calc.h
@@ -32,7 +32,8 @@ void process_cmd(char cmd);
 //push_decn is equivalent to "set_x()" if no_lift is true
 void push_decn(__xdata const char* signif_str, __xdata exp_t exponent);
 extern uint8_t NoLift;
-extern __bit IsShifted;
+extern __bit IsShiftedUp;
+extern __bit IsShiftedDown;
 
 void clear_x(void);
 __xdata dec80* get_x(void);
diff --git a/src/decn/decn.c b/src/decn/decn.c
index 5322ea5..6419b84 100644
--- a/src/decn/decn.c
+++ b/src/decn/decn.c
@@ -1393,6 +1393,13 @@ void to_radian_decn(void) {
 	div_decn();
 }
 
+void pi_decn(void) {
+	set_dec80_zero(&BDecn);
+	BDecn.lsu[0] = 5; // 0.5 00 ..
+	copy_decn(&AccDecn, &DECN_2PI);
+	mult_decn();
+}
+
 
 static void set_str_error(void){
 	Buf[0] = 'E';
diff --git a/src/decn/decn.h b/src/decn/decn.h
index af9803f..cdffaa0 100644
--- a/src/decn/decn.h
+++ b/src/decn/decn.h
@@ -92,6 +92,7 @@ void tan_decn(void);
 void arctan_decn(void);
 void to_degree_decn(void);
 void to_radian_decn(void);
+void pi_decn(void);
 
 //Buf should hold at least 18 + 4 + 5 + 1 = 28
 #define DECN_BUF_SIZE 28
diff --git a/src/main.c b/src/main.c
index 9a2d39f..0fdcf70 100644
--- a/src/main.c
+++ b/src/main.c
@@ -307,7 +307,7 @@ int main()
 			switch(KEY_MAP[I_Key]){
 				//////////
 				case '0': {
-					if (IsShifted){
+					if (IsShiftedUp){
 						//off
 						TURN_OFF();
 					} else {
@@ -343,7 +343,7 @@ int main()
 				case '7': //fallthrough
 				case '8': //fallthrough
 				case '9': {
-					if (IsShifted){
+					if (IsShiftedUp || IsShiftedDown){
 						finish_process_entry();
 					} else if ( EnteringExp >= ENTERING_EXP){
 						if ( Exp_i == 0){
@@ -368,7 +368,7 @@ int main()
 				} break;
 				//////////
 				case '.': {
-					if (IsShifted){
+					if (IsShiftedUp || IsShiftedDown){
 						//STO
 						finish_process_entry();
 					} else {
@@ -391,7 +391,7 @@ int main()
 				} break;
 				//////////
 				case '=': {
-					if (IsShifted){ //RCL
+					if (IsShiftedUp || IsShiftedDown){ //RCL
 						finish_process_entry();
 					} else { //Enter
 						//track stack lift
@@ -401,9 +401,10 @@ int main()
 				} break;
 				//////////
 				case 'c': {
-					if (IsShifted || is_entering_done()){
+					if (IsShiftedUp || IsShiftedDown || is_entering_done()){
 						//clear
-						IsShifted = 0;
+						IsShiftedUp = 0;
+						IsShiftedDown = 0;
 						NoLift = 1;
 						entering_done();
 						EnteringExp = ENTERING_DONE_CLEARED;
@@ -521,12 +522,15 @@ int main()
 		LCD_ClearToEnd(1);
 
 		//print shifted status
-		if (IsShifted){
+		if (IsShiftedUp){
 			TERMIO_PutChar('^');
 #if defined(STACK_DEBUG) && defined(SHOW_STACK)
 			TERMIO_PutChar(' ');
 			TERMIO_PrintU8(stack_max);
+			TERMIO_PutChar(' ');
 #endif
+		} else if (IsShiftedDown){
+			TERMIO_PutChar('v');
 		}
 
 #ifdef DESKTOP