--- a/Makefile	Fri Feb 25 18:58:43 2011 -0500
+++ b/Makefile	Tue Mar 01 02:39:27 2011 -0500
@@ -8,7 +8,7 @@
 CFLAGS=-g -fno-strict-aliasing -fno-builtin -nostdinc -nostdlib -Wall -m64 -I include/ -O2
 LDFLAGS=-m elf64_s390
 
-OBJS=src/init.o src/io.o
+OBJS=src/init.o src/io.o src/std.o src/stack.o src/operations.o
 
 .PHONY: all build clean tags
 

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/include/operations.h	Tue Mar 01 02:39:27 2011 -0500
@@ -0,0 +1,17 @@
+#ifndef __OPERATIONS_H
+#define __OPERATIONS_H
+
+#include <std.h>
+#include <stack.h>
+
+enum Operation {PRINT, ADD, SUB, MULT, DIV, DUP, MAXOP};
+const char operationNames[MAXOP][10] = {".", "+", "-", "*", "/", "dup"};
+
+void print(struct Stack *stack);
+void add(struct Stack *stack);
+void sub(struct Stack *stack);
+void mult(struct Stack *stack);
+void div(struct Stack *stack);
+void dup(struct Stack *stack);
+
+#endif //__OPERATIONS_H

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/include/stack.h	Tue Mar 01 02:39:27 2011 -0500
@@ -0,0 +1,16 @@
+#ifndef __STACK_H
+#define __STACK_H
+
+typedef int eltType;
+
+struct Stack {
+	int isEmpty;
+	unsigned int top;
+	eltType values[100];
+};
+
+eltType pop(struct Stack *stack);
+void push(struct Stack *stack, eltType val);
+void initStack(struct Stack *stack);
+
+#endif //__STACK_H

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/include/std.h	Tue Mar 01 02:39:27 2011 -0500
@@ -0,0 +1,15 @@
+#ifndef __STD_H
+#define __STD_H
+
+extern void itoa(int n, char *a);
+extern int atoi(char *a);
+
+extern void sPrint(char *a);
+void iPrint(int n);
+extern void sGet(char *a, unsigned int n);
+
+extern int strcmp(char *a, char *b);
+
+int arrayLookup(char *text, const char array[][10], int last);
+
+#endif

--- a/src/init.c	Fri Feb 25 18:58:43 2011 -0500
+++ b/src/init.c	Tue Mar 01 02:39:27 2011 -0500
@@ -1,9 +1,65 @@
 /*
  * This is where everything starts
  */
+
+#include <std.h>
+#include <operations.h>
+#include <stack.h>
+
+void dumpBuffer(char *a, int b)
+{
+	int i;
+	for(i = 0; i < b; i++) {
+		int foo = (int) a[i];
+		char c[10];
+		itoa(foo, c);
+		sPrint(c);
+		sPrint("\n");
+	}
+}
+
 void start(u64 __memsize)
 {
-	putline("Hello\n", 6);
+	/*
+	int foo;
+	char bar[20];
+	char string[20] = "This is a test";
+	dumpBuffer(string, 10);
+	sPrint("Please enter an operation: ");
+	foo = getline(string, 10);
+	itoa(foo, bar);
+	sPrint(bar);
+	sPrint("\n");
+	dumpBuffer(string, 10);
+	sPrint("Please enter a second operation: ");
+	sGet(string, 4);
+	dumpBuffer(string, 10);
+	*/
+
+	void (*operation[MAXOP])(struct Stack*) = {NULL};
+	operation[0] = print;
+	operation[1] = add;
+	operation[2] = sub;
+	operation[3] = mult;
+	operation[4] = div;
+	operation[5] = dup;
+
+	struct Stack theStack;
+	struct Stack *stack = &theStack;
+	initStack(stack);
+	while(1) {
+		int opVal;
+		char input[20];
+		sPrint("Please enter an operation or value: ");
+		sGet(input, 20);
+		opVal = arrayLookup(input, operationNames, MAXOP);
+		if(opVal != MAXOP) {
+			(*operation[opVal]) (stack); //call the function array
+		} else {
+			opVal = atoi(input);
+			push(stack, opVal);
+		}
+	}
 
 	for(;;)
 		;

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/operations.c	Tue Mar 01 02:39:27 2011 -0500
@@ -0,0 +1,47 @@
+//#include <operations.h>
+#include <std.h>
+#include <stack.h>
+
+void print(struct Stack *stack)
+{
+	eltType val = pop(stack);
+	char output[10];
+	itoa(val, output);
+	sPrint(output);
+	sPrint("\n");
+}
+
+void add(struct Stack *stack)
+{
+	eltType first = pop(stack);
+	eltType sec = pop(stack);
+	push(stack, sec + first); //yeah, this should be obvious
+}
+
+void sub(struct Stack *stack)
+{
+	eltType first = pop(stack);
+	eltType sec = pop(stack);
+	push(stack, sec - first);
+}
+
+void mult(struct Stack *stack)
+{
+	eltType first = pop(stack);
+	eltType sec = pop(stack);
+	push(stack, sec*first);
+}
+
+void div(struct Stack *stack)
+{
+	eltType first = pop(stack);
+	eltType sec = pop(stack);
+	push(stack, sec/first);
+}
+
+void dup(struct Stack *stack)
+{
+	eltType val = pop(stack);
+	push(stack, val);
+	push(stack, val);
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/stack.c	Tue Mar 01 02:39:27 2011 -0500
@@ -0,0 +1,32 @@
+#include <stack.h>
+
+eltType pop(struct Stack *stack)
+{
+	if(stack->isEmpty) {
+		sPrint("ERROR: STACK IS EMPTY.\n");
+		return -1;
+	} else if(stack->top == 0) {
+		stack->isEmpty = 1;
+		return stack->values[stack->top];
+	} else if(stack->top < 0) {
+		return 0; //TODO figure out a better way to handle errors
+	} else {
+		return stack->values[stack->top--];
+	}
+}
+
+void push(struct Stack *stack, eltType val)
+{
+	if(stack->isEmpty) {
+		stack->isEmpty = 0;
+		stack->values[stack->top] = val;
+	} else {
+		stack->values[++stack->top] = val;
+	}
+}
+
+void initStack(struct Stack *stack)
+{
+	stack->isEmpty = 1;
+	stack->top = 0;
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/std.c	Tue Mar 01 02:39:27 2011 -0500
@@ -0,0 +1,72 @@
+void itoa(int n, char *a)
+{
+	if(n < 0) {
+		*a++ = '-';
+		n *= -1;
+	}
+	char *b = a;
+	if(!n) *b++ = '0';
+	for(; n; b++) {
+		*b = n%10 + '0';
+		n = n/10;
+	}
+	*b-- = '\0';
+	for(; a < b; a++, b--) { //reverse
+		char temp = *b;
+		*b = *a;
+		*a = temp;
+	}
+}
+
+int atoi(char *a)
+{
+	int neg = 0;
+	int n = 0;
+	if(*a == '-') {
+		neg = 1;
+		a++;
+	}
+	while(*a >='0' && *a <= '9')
+		n = n*10 + (*a++ - '0');
+	if(neg) n *= -1;
+	return n;
+}
+
+void sPrint(char *a)
+{
+	char *b = a;
+	while(*b && *++b);
+	putline(a, b - a);
+}
+
+void iPrint(int n)
+{
+	char string[10];
+	itoa(n, string);
+	sPrint(string);
+}
+
+int strcmp(char *a, char *b)
+{
+	while(1) {
+		if(*a - *b) return *a - *b;
+		if(*a == '\0') return 0;
+		a++;
+		b++;
+	}
+	return -1;
+}
+
+void sGet(char *a, unsigned int n) //TODO bug Jeff about getline
+{
+	int length = getline(a, n);
+	a[(length < n)?length:n - 1] = '\0';
+}
+
+int arrayLookup(char *text, const char array[][10], int last)
+{
+	int i;
+	for(i = 0; i < last; i++)
+		if(!strcmp(array[i], text)) return i;
+	return last;
+}