diff --git a/assembly.c b/assembly.c
index 107ff8f..0f237eb 100644
--- a/assembly.c
+++ b/assembly.c
@@ -61,6 +61,10 @@
 //  +-------+----------------------------------+--------------+
 //  | 5'h5  | Jump if carry flag is not set    |      NO      |
 //  +-------+----------------------------------+--------------+
+//  | 5'h6  | Jump if sign flag is set         |      NO      |
+//  +-------+----------------------------------+--------------+
+//  | 5'h7  | Jump if sign flag is not set     |      NO      |
+//  +-------+----------------------------------+--------------+
 //  | 5'h10 | Unconditional ret                |      NO      |
 //  +-------+----------------------------------+--------------+
 //  | 5'h11 | Unconditional call               |      NO      |
@@ -72,6 +76,10 @@
 //  | 5'h14 | Call if carry flag is set        |      NO      |
 //  +-------+----------------------------------+--------------+
 //  | 5'h15 | Call if carry flag is not set    |      NO      |
+//  +-------+----------------------------------+--------------+
+//  | 5'h16 | Call if sign flag is set         |      NO      |
+//  +-------+----------------------------------+--------------+
+//  | 5'h17 | Call if sign flag is not set     |      NO      |
 //
 //
 //  |       |                                  |              |
@@ -180,6 +188,12 @@ char *disassemble(uint32_t opcode_be){
 			case 0x0F:
 				snprintf(ret,MAX_INSTRUCTION_LENGTH,"MOV $%06X,%%SP",val);
 				break;
+			case 0x06:
+			case 0x07:
+			case 0x16:
+			case 0x17:
+				snprintf(ret,MAX_INSTRUCTION_LENGTH,"%s,%s $%06X",(opcode_num&0x10)?"CALL":"JMP",opcode_num&1?"NS":"S",val);
+				break;
 			default:
 				snprintf(ret,MAX_INSTRUCTION_LENGTH,"UNRECOGNISED INSTR");
 				break;
@@ -369,9 +383,11 @@ int64_t assemble_line(char *line, struct assembler_context_t *assembler_context)
 		return -1;//empty line or comment
 	if( (strncmp(line,"JMP,",4)==0) || (strncmp(line,"JMP ",4)==0) || ((call=strncmp(line,"CALL ",5))==0) ){
 		if(!call){
+			/*if it was a call*/
 			x=4;
 			opcode=0x10;
 		}else{
+			/*if it wasn't*/
 			x=3;
 			opcode=0x00;
 		}
@@ -385,6 +401,9 @@ int64_t assemble_line(char *line, struct assembler_context_t *assembler_context)
 			}else if(line[x]=='C'){
 				opcode|=0x04;
 				x++;
+			}else if(line[x]=='S'){
+				opcode|=0x06;
+				x++;
 			}else if(line[x]=='N'){
 				x++;
 				if(line[x]=='Z'){
@@ -393,6 +412,9 @@ int64_t assemble_line(char *line, struct assembler_context_t *assembler_context)
 				}else if(line[x]=='C'){
 					opcode|=0x09;
 					x++;
+				}else if(line[x]=='S'){
+					opcode|=0x07;
+					x++;
 				}else
 					return -2;
 			}else
diff --git a/cpu.c b/cpu.c
index ace01f4..1a3140e 100644
--- a/cpu.c
+++ b/cpu.c
@@ -84,17 +84,23 @@ int decode(struct simdata_t *simdata){
 				case 0x03:
 				case 0x04:
 				case 0x05:
+				case 0x06:
+				case 0x07:
 				case 0x11:
 				case 0x12:
 				case 0x13:
 				case 0x14:
 				case 0x15:
+				case 0x16:
+				case 0x17:
 					switch(opcode){
 						case 0x01: case 0x11: simdata->exec_data->COND=COND_NONE; break;
 						case 0x02: case 0x12: simdata->exec_data->COND=COND_ZERO; break;
 						case 0x03: case 0x13: simdata->exec_data->COND=COND_NZERO; break;
 						case 0x04: case 0x14: simdata->exec_data->COND=COND_CARRY; break;
 						case 0x05: case 0x15: simdata->exec_data->COND=COND_NCARRY; break;
+						case 0x06: case 0x16: simdata->exec_data->COND=COND_SIGN; break;
+						case 0x07: case 0x17: simdata->exec_data->COND=COND_NSIGN; break;
 						default: return 1;
 					}
 					simdata->exec_data->out_op->OP_ADDR=IMMEDIATE;
@@ -350,6 +356,8 @@ int exec(struct simdata_t *simdata){
 					case COND_NZERO:  condition=!(simdata->registers->FLAGS&1); break;
 					case COND_CARRY:  condition=simdata->registers->FLAGS&2;    break;
 					case COND_NCARRY: condition=!(simdata->registers->FLAGS&2); break;
+					case COND_SIGN:   condition=simdata->registers->FLAGS&4;    break;
+					case COND_NSIGN:  condition=!(simdata->registers->FLAGS&4); break;
 				}
 				switch(simdata->exec_data->COND){
 					case COND_NONE:
@@ -404,6 +412,8 @@ int exec(struct simdata_t *simdata){
 								simdata->registers->GPR[simdata->exec_data->in_op1->data];
 							simdata->registers->FLAGS=(simdata->registers->FLAGS&0xFFFFFFFD)|
 								(simdata->registers->GPR[simdata->exec_data->out_op->data] > simdata->registers->GPR[simdata->exec_data->in_op1->data])<<1;
+							simdata->registers->FLAGS=(simdata->registers->FLAGS&0xFFFFFFFB)|
+								(simdata->registers->GPR[simdata->exec_data->in_op2->data]<simdata->registers->GPR[simdata->exec_data->in_op1->data])<<2;
 
 							simdata->exec_data->cycles_left=delay_values[RR_SIMPL_INDX];
 
diff --git a/cpu.h b/cpu.h
index dee908d..f574b5f 100644
--- a/cpu.h
+++ b/cpu.h
@@ -65,7 +65,9 @@ enum COND_t{
 	COND_ZERO,
 	COND_NZERO,
 	COND_CARRY,
-	COND_NCARRY
+	COND_NCARRY,
+	COND_SIGN,
+	COND_NSIGN
 };
 
 struct exec_data_t {
diff --git a/programs/quicksort.asm b/programs/quicksort.asm
index 0b3b919..fb4788c 100644
--- a/programs/quicksort.asm
+++ b/programs/quicksort.asm
@@ -1,5 +1,42 @@
 MOV $0xFF0000,%SP
-MOV %SP,%R2
+MOV $0x0000,%R0h
+MOV $DATA,%R0l
 PUSH %R0
-MOV %SP,%R2
+MOV $DATA_END,%R0l
+PUSH %R0
+CALL $QUICKSORT
 HALT
+
+:QUICKSORT
+#Get parameters from stack
+MOV %SP,%R0
+MOV $0x0000,%R1h
+MOV $0x0004,%R1l
+SUB %R1,%R0
+SUB %R1,%R0
+MOV (%R0),%R2
+SUB %R1,%R0
+MOV (%R0),%R3
+
+#Compare input and quit if start >= end
+CMP %R2,%R3
+JMP,NS $BAIL
+
+ADD %R2,%R3
+
+:BAIL
+RET
+
+
+:DATA
+DDW $0x00000000
+DDW $0x00000004
+DDW $0x00000009
+DDW $0x00000031
+DDW $0x000000BB
+DDW $0x0000000e
+DDW $0x00000002
+DDW $0x000000BB
+DDW $0x01000000
+:DATA_END
+DDW $0xFFFFFFFF