diff --git a/CMakeLists.txt b/CMakeLists.txt
index a913e68..c672846 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -12,4 +12,5 @@
 		WORKING_DIRECTORY ${CMAKE_SOURCE_DIR})
 endif()
 
-add_executable(emu-6502 main.c cpu.c cpu.h dbg.c dbg.h instructions.h)
+add_executable(6502 main.c cpu.c cpu.h dbg.c dbg.h instructions.h)
+target_link_libraries(6502 readline)
\ No newline at end of file
diff --git a/dbg.c b/dbg.c
index bdc2b31..f5ca437 100644
--- a/dbg.c
+++ b/dbg.c
@@ -11,10 +11,13 @@
 	while (true)
 	{
 		char *input = readline("\033[33m> \033[0m");
-		if (!input)
+		if (!input || !*input)
 			continue;
 
 		char *tok = strtok(input, " \t\r\n\v");
+
+		if (!tok || !*tok)
+			continue;
 		
 		if (!strcmp(tok, "step") || !strcmp(tok, "s"))
 		{
@@ -29,22 +32,34 @@
 				{
 					uint16_t addr = strtol(tok + 1, &ok, 16);
 
-					if (ok == 0)
-					{
-						printf("Memory:\n");
-						printf("\t$%x	%x\n", addr, cpu->mem[addr]);
+					printf("Memory:\n");
+					printf("\t$%x	%x\n", addr, cpu->mem[addr]);
+					if (addr < 0xFFFF)
 						printf("\t$%x	%x\n", addr + 1, cpu->mem[addr + 1]);
-					}
 				}
 				else
 				{
-					printf("Registers:\n");
-
-					#define R(r) printf("\t" #r ":	%x\n", cpu->regs[r]);
-						REGISTERS
-					#undef R
+					printf("Expected an address as an argument in the form "
+						"$1234, not %s\n", tok);
 				}
 			}
+			else
+			{
+				printf("Registers:\n");
+
+				#define R(r) printf("\t" #r ":\t%x\n", cpu->regs[r]);
+					REGISTERS
+				#undef R
+			}
+		}
+		else if (!strcmp(tok, "quit") || !strcmp(tok, "exit"))
+		{
+			printf("Bye\n");
+			return;
+		}
+		else
+		{
+			printf("Unknown command %s\n", tok);
 		}
 
 		add_history(input);
diff --git a/main.c b/main.c
index 8e6ec52..5ab918d 100644
--- a/main.c
+++ b/main.c
@@ -1,5 +1,7 @@
 #include "cpu.h"
+#include "dbg.h"
 
+#include <bits/getopt_core.h>
 #include <ctype.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -7,44 +9,71 @@
 
 int main(int argc, char **argv)
 {
-	printf("6502 Emulator\n");
-
-	uint8_t disflag = 0,
+	bool disflag = 0,
 		runflag = 0,
-		helpflag = 0;
+		helpflag = 0,
+		debugflag = 0,
+		should_read = 0;
+
+	FILE *input = stdin;
 
 	char c;
 
-	while ((c = getopt(argc, argv, "drh")) != -1)
+	while ((c = getopt(argc, argv, "Ddrhi:")) != -1)
 	{
 		switch (c)
 		{
-			case 'd':
-				disflag = 1;
-				break;
-			case 'r':
-				runflag = 1;
-				break;
-			case 'h':
-			case '?':
-				helpflag = 1;
-				break;
+		case 'd':
+			disflag = true;
+			should_read = true;
+			break;
+		case 'r':
+			runflag = true;
+			should_read = true;
+			break;
+		case 'D':
+			debugflag = true;
+			should_read = true;
+			break;
+		case 'i':
+			input = fopen(optarg, "r");
+			break;
+		case 'h':
+		case '?':
+			helpflag = 1;
+			break;
 		}
 	}
 
 	if (helpflag)
 	{
-		printf("-r to run, -d to disassemble");
+		printf("6502 emulator, disassembler and debugger\n"
+			"Usage:\n"
+			"	-d disassemble input\n"
+			"	-r run input\n"
+			"	-D debug input (open debug prompt)\n"
+			"	-i <input> set input file, defaults to standard input\n"
+			"	-h, -? show this help page\n");
 		return 0;
 	}
 
-	cpu_t cpu = new_cpu();
-	fread(cpu.mem, 0xFFFF, 1, stdin);
+	cpu_t cpu;
+
+	if (should_read)
+	{
+		cpu = new_cpu();
+		fread(cpu.mem, 0xFFFF, 1, input);
+	}
 
 	if (disflag)
 	{
 		disas(&cpu);
 	}
-
-	free_cpu(&cpu);
+	else if (debugflag)
+	{
+		debug(&cpu);
+	}
+	
+	if (should_read)
+		free_cpu(&cpu);
 }