diff --git a/src/assemble.c b/src/assemble.c
index 856a097..967b02e 100755
--- a/src/assemble.c
+++ b/src/assemble.c
@@ -1,8 +1,34 @@
 #include <stdlib.h>
 #include <stdio.h>
+#include "a64instruction/a64instruction.h"
 #include "parser.h"
 #include "fileio.h"
+#include "parser.h"
+#include "twopassassembly.c"
 
 int main(int argc, char **argv) {
+  // Check the arguments
+  if (argc < 3) {
+    fprintf(stderr, "Error: A source file and an object output file are required. Syntax: ./assemble <file_in> <file_out>");
+    return EXIT_FAILURE;
+  }
+
+  // Load the source file into memory
+  char **source = readAssemblyFile(argv[1]);
+
+  // Parse the source file
+  a64inst_instruction *instructions = parse(source);
+  
+  // First Pass: Create the symbol table
+  st *table = firstPass(instructions, 1000); // 1000 is just a temp fix.
+
+  // Second Pass: Assemble the instructions
+  word *binary = secondPass(instructions, 1000, table); // 1000 is just a temp fix.
+
+  // Write the binary to the output file
+  writeBinaryFile(binary, argv[2], 1000); // 1000 is just a temp fix.
+
+  /* TODO: FREE MEMORY!! */
+
   return EXIT_SUCCESS;
 }
diff --git a/src/fileio.c b/src/fileio.c
index 85fd8d1..8be2e38 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -1,5 +1,7 @@
 #include <stdio.h>
 #include <string.h>
+#include "global.h"
+#include "fileio.h"
 
 #define MAX_ASM_LINE_LENGTH 30
 
diff --git a/src/fileio.h b/src/fileio.h
index a2d4262..88e9cca 100644
--- a/src/fileio.h
+++ b/src/fileio.h
@@ -5,5 +5,7 @@
 
 #define EXIT_FAILURE 1
 
-extern byte *fileio_loadBin(const char *filePath, size_t memorySize);
+char **readAssemblyFile(char inputFile[]);
+int writeBinaryFile(word instrs[], char outputFile[], int numInstrs);
+
 #endif
diff --git a/src/parser.c b/src/parser.c
index 8cb6609..a66b6f3 100644
--- a/src/parser.c
+++ b/src/parser.c
@@ -3,7 +3,6 @@
 #include <string.h>
 #include <stdbool.h>
 #include "parser.h"
-
 #include "a64instruction/a64instruction.h"
 
 //takes input string, read from asm file and returns
@@ -188,16 +187,15 @@ void tokeniseOperands(char* str, int *operandCount, char *operands[], int *numOp
 
 //takes inputted assembly line and returns a 
 //pointer to an abstract representation of the instruction
-a64inst_instruction *parser(char asmLine[]){
+void parser_instruction(char asmLine[], a64inst_instruction *instr) {
     int numOperands = 0;
-    a64inst_instruction *instr = malloc(sizeof(a64inst_instruction)); 
     if (instr == NULL){
         exit(EXIT_FAILURE);
     }
 
     if(strcmp(asmLine, HALT_ASM_CMD) == 0){
         instr->type = a64inst_HALT;
-        return(instr);
+        return;
     }
 
     //"opcode operand1, {operand2}, ..."
@@ -252,7 +250,19 @@ a64inst_instruction *parser(char asmLine[]){
         
     }
 
-    return(instr);
-
 }
 
+// Takes an array of strings, each string representing an assembly instruction.
+// Returns an array of a64inst_instruction pointers, each representing an instruction.
+// Note. The array of strings must be NULL-terminated????
+a64inst_instruction *parse(char **asmLines) {
+    a64inst_instruction *instructions = malloc(sizeof(a64inst_instruction) * 1000);
+
+    int i = 0;
+    while (asmLines[i] != NULL) {
+        parser_instruction(asmLines[i], &instructions[i]);
+        i++;
+    }
+
+    return instructions;
+}
diff --git a/src/parser.h b/src/parser.h
index e303b58..1f7ab70 100644
--- a/src/parser.h
+++ b/src/parser.h
@@ -1,2 +1,6 @@
+#include "a64instruction/a64instruction.h"
+
 #define OPERAND_DELIMITER ", "
 #define HALT_ASM_CMD "and x0, x0, x0"
+
+a64inst_instruction *parse(char **asmLines);
diff --git a/src/twopassassembly.c b/src/twopassassembly.c
index e6899d5..b4ecdec 100644
--- a/src/twopassassembly.c
+++ b/src/twopassassembly.c
@@ -178,11 +178,12 @@ word ldl(a64inst_instruction cI) {
     return out;
 }
 
-void secondPass(a64inst_instruction instrs[], int numInstrs, st* table, word arr[]) {
+word *secondPass(a64inst_instruction instrs[], int numInstrs, st* table) {
     // TODO:
     // iterate over instructions again, this time replacing labels
     // with values from symbol table
     // after a line has had all the values replaced, assemble it and append
+    word *arr = (word*)malloc(sizeof(word) * numInstrs);
     int index = 0;
     for (int i = 0; i < numInstrs; i++) {
         a64inst_instruction cI = instrs[i];
@@ -221,5 +222,5 @@ void secondPass(a64inst_instruction instrs[], int numInstrs, st* table, word arr
                 break;
         }
     }
-    return;
+    return arr;
 }