diff --git a/kernel/functions.h b/kernel/functions.h
new file mode 100644
index 0000000..025c6be
--- /dev/null
+++ b/kernel/functions.h
@@ -0,0 +1,94 @@
+//functions.h
+//05/07/03 Josh Holtrop
+//for HOS
+//Modified: 02/26/04
+
+#ifndef __HOS_FUNCTIONS__
+#define __HOS_FUNCTIONS__ __HOS_FUNCTIONS__
+
+#include "hos_defines.h"
+#include "sys/io.h"
+
+extern dword _code;
+extern dword _bss;
+extern dword _end;
+
+//Enables (SeTs) Interrupt Flag on the processor
+static inline void enable_ints()
+{
+	asm("sti");
+}
+
+//Disables (CLears) Interrupt Flag on the processor
+static inline void disable_ints()
+{
+	asm("cli");
+}
+
+//Restarts the computer
+static inline void restart()
+{
+ 	enable_ints();
+ 	byte temp;
+	do
+	{
+		temp = inportb(0x64);
+		if (temp & 1)
+		inportb(0x60);
+	} while(temp & 2);
+
+
+	outportb (0x64, 0xfe);
+	for (;;) {}
+}
+
+//Halts (freezes) the computer
+static inline void halt()
+{
+ 	asm("cli");
+ 	asm("hlt");
+ 	while (1) ;
+}
+
+//Initializes 8253 Programmable Interrupt Timer
+static inline void timer_init()
+{
+ 	//set timer : 2e9c = 100hz
+	outportb(0x43, 0x34);
+	outportb(0x40, 0x9c); //lsb
+	outportb(0x40, 0x2e); //msb
+}
+
+//Returns the size of the kernel (code & data)
+// - this does include the bss section
+// - this should be 4kb aligned per the linker script
+// - this is the amount of RAM the kernel code, data, & bss take
+static inline dword kernel_size_used()
+{
+	return (dword)(&_end)-(dword)(&_code);
+}
+
+//Returns the size of the kernel (code & data)
+// - this does not include the bss section
+// - this should be 4kb aligned per the linker script
+// - this should be the size of kernel.bin
+static inline dword kernel_size()
+{
+	return (dword)(&_bss)-(dword)(&_code);
+}
+
+//converts a binary-coded-decimal byte to its decimal equivalent
+static inline byte bcd2byte(byte bcd)
+{
+ 	return (10 * ((bcd & 0xF0) >> 4)) + (bcd & 0x0F);
+}
+
+//converts a binary-coded-decimal byte to its decimal equivalent
+static inline byte byte2bcd(byte bite)
+{
+	return ((bite / 10) << 4) | (bite % 10);
+}
+
+#endif
+
+
diff --git a/kernel/kernel.c b/kernel/kernel.c
index b8f4e5d..8aa347f 100644
--- a/kernel/kernel.c
+++ b/kernel/kernel.c
@@ -3,6 +3,7 @@
 #include "multiboot.h"
 #include "module.h"
 #include "asmfuncs.h"
+#include "functions.h"
 #include "mm/mm.h"
 #include "mm/vmm.h"
 
@@ -13,6 +14,7 @@ mb_module_t mb_modules[MAX_MODULES];
 mb_apm_t mb_apm_table;
 byte real_mode_module;
 char mb_cmdline[256];
+int criticalCounter;
 
 /* This function runs in segmented memory - 0xC000_0000 is mapped to 0x0 but 0x0
    itself is an invalid linear address. Therefore, the multiboot information addresses
@@ -104,3 +106,16 @@ void isr(u32_t num)
 	}
 }
 
+void k_enter_critical()		// functions for implementing "atomic actions"
+{
+	disable_ints();
+	criticalCounter++;
+}
+
+void k_leave_critical()
+{
+	criticalCounter--;
+	if (!criticalCounter)
+		enable_ints();
+}
+
diff --git a/kernel/kernel.h b/kernel/kernel.h
index 67a6163..271a531 100644
--- a/kernel/kernel.h
+++ b/kernel/kernel.h
@@ -6,19 +6,19 @@
 #include "multiboot.h"
 
 typedef struct {
-	void	*vid_addr;	//address of LFB, 0 if console mode
-	u32_t	width;		//width in pixels or columns if vid_mem == 0
-	u32_t	height;		//height in pixels or columns if vid_mem == 0
-	u32_t	vid_mem;	//amount of memory for video buffer
-	u32_t	bpp;		//bits per pixel - 16/24/32
+	void	*vid_addr;	// address of LFB, 0 if console mode
+	u32_t	width;		// width in pixels or columns if vid_mem == 0
+	u32_t	height;		// height in pixels or columns if vid_mem == 0
+	u32_t	vid_mem;	// amount of memory for video buffer
+	u32_t	bpp;		// bits per pixel - 16/24/32
 } __attribute__ ((packed)) real_mode_param_t;
 
 /* returns true to callee if we should jump to a real mode module */
 int k_mbsave(mb_info_t *mbinfo, unsigned int mb_magic);
-
 void k_init();
-
 void isr();
+void k_enter_critical();	// functions for implementing "atomic actions"
+void k_leave_critical();
 
 #endif
 
diff --git a/kernel/mm/vmm.c b/kernel/mm/vmm.c
index 021f4bb..15ba8a4 100644
--- a/kernel/mm/vmm.c
+++ b/kernel/mm/vmm.c
@@ -5,6 +5,7 @@
 // Modified: 07/13/04
 
 #include "hos_defines.h"
+#include "kernel.h"
 #include "mm/vmm.h"
 #include "asmfuncs.h"
 #include "mm/mm.h"
@@ -24,7 +25,13 @@ void	vmm_init()
 	int i;
 	for (i = 0; i < mb_info_block.mods_count; i++)	//page in the kernel modules
 		vmm_map_range((void*)mb_modules[i].mod_start, (void*)mb_modules[i].mod_end- 1, mb_modules[i].mod_start - VIRT_OFFSET);
-
+	vmm_heb_init(initialHEB);
+	vmm_addToQueue(VMM_HE_UNUSED, initialHEB[0]);
+	HeapEntry_t *wilderness = vmm_stripUnusedEntry();
+	wilderness->base = HEAP_START;
+	wilderness->length = HEAP_LENGTH;
+	wilderneww->next = 0;
+	vmm_addToQueue(VMM_HE_HOLE, wilderness);
 }
 
 
@@ -40,32 +47,33 @@ u32_t	vmm_map(void *virt)
 
 
 // This function maps a virtual address to a physical address using the page directory / page table
-void	vmm_map1(unsigned int virt, unsigned int physical)
+int	vmm_map1(unsigned int virt, unsigned int physical)
 {
 	unsigned int pde = virt >> 22;
 	unsigned int pte = (virt & 0x003FF000) >> 12;
 	unsigned int *pageTables = (unsigned int *)0xFFFFF000;	//this is the location of the page directory
-	if (!(pageTables[pde] & 0x01))		//the page directory entry does not exist, we must allocate a page for it
+	if (!(pageTables[pde] & 0x01))		//the page directory entry is not present, we must allocate a page table
 	{
-		u32_t newpagetable = mm_palloc();
+		u32_t newpagetable;
+		if (!(newpagetable = mm_palloc())
+			return 1;		//out of physical memory
 		pageTables[pde] = newpagetable | 0x03;
 		invlpg_(virt);		//in case it was cached, so we can fill page table safely
-		unsigned int *newpteptr = (unsigned int *)(0xFFC00000 | (pde << 12));	//points to first unsigned int of newly allocated page table
-		int a;
-		for (a = 0; a < 1024; a++)
-			*newpteptr++ = 0;
+		memsetd((void*)(0xFFC00000 | (pde << 12)), 0, 1024);	//zero out new page table
 	}
 	*(unsigned int *)(0xFFC00000 | (pde << 12) | (pte << 2)) = (physical & 0xFFFFF000) | 0x03;
 	invlpg_(virt);
+	return 0;
 }
 
 
 // This function maps a variable number of pages in a row
-void	vmm_mapn(unsigned int virt, unsigned int physical, unsigned int n)
+int	vmm_mapn(unsigned int virt, unsigned int physical, unsigned int n)
 {
 	while (n > 0)
 	{
-		vmm_map1(virt, physical);
+		if (vmm_map1(virt, physical))
+			return 1;	// error mapping page
 		virt += 4096;
 		physical += 4096;
 		n--;
@@ -96,10 +104,11 @@ void	vmm_unmapn(unsigned int virt, unsigned int n)
 int	vmm_map_range(void *virt_start, void *virt_end, u32_t phys_start)
 {
 	if (virt_end < virt_start)
-		return 1;	//invalid region
+		return 1;	// invalid region
 	while (virt_start < virt_end)
 	{
-		vmm_map1((u32_t)virt_start, phys_start);
+		if (vmm_map1((u32_t)virt_start, phys_start))
+			return 2;	// out of memory
 		virt_start += 4096;
 		phys_start += 4096;
 	}
@@ -107,6 +116,20 @@ int	vmm_map_range(void *virt_start, void *virt_end, u32_t phys_start)
 }
 
 
+void *kmalloc(u32_t size)
+{
+	k_enter_critical();
+	k_leave_critical();
+}
+
+
+void *vmm_palloc()
+{
+	k_enter_critical();
+	k_leave_critical();
+}
+
+
 // This function allocates and zeros memory for the given number of objects,
 //  given the size of each object
 /*
@@ -158,7 +181,6 @@ int vmm_countHeapEntries(HeapEntry_t *he)
 }
 
 
-
 // This function follows a chain of HeapEntry objects and returns a pointer to the last one
 HeapEntry_t *vmm_followChain(HeapEntry_t *he)
 {
@@ -169,18 +191,24 @@ HeapEntry_t *vmm_followChain(HeapEntry_t *he)
 
 
 // This function breaks an unused chunk from its queue and returns a pointer to it
-HeapEntry_t *vmm_getUnusedChunk()
+HeapEntry_t *vmm_getUnusedEntry()
 {
 	if (heapEntryQueues[VMM_HE_UNUSED].count < 5)
 	{
-		heapEntryQueues[VMM_HE_UNUSED].count += 256;//not good idea
-		HeapEntryBlock_t *newHEB = vmm_palloc();   //INFINITE LOOP?
-		vmm_mcb_init(newHEB);
+		HeapEntry_t *wilderness = vmm_followChain(
+		HeapEntryBlock_t *newHEB;
+		vmm_heb_init(newHEB);
 		vmm_addToQueue(VMM_HE_UNUSED, newHEB);
-		heapEntryQueues[VMM_HE_UNUSED].count -= 256;
 	}
+	return vmm_stripUnusedEntry();
+}
+
+
+// Return pointer to an unused HeapEntry object, ASSUMES THERE IS ONE PRESENT IN QUEUE
+HeapEntry_t *vmm_stripUnusedEntry()
+{
 	HeapEntry_t *he = heapEntryQueues[VMM_HE_UNUSED].start;
-	heapEntryQueues[VMM_HE_UNUSED].start = he->link;
+	heapEntryQueues[VMM_HE_UNUSED].start = he->next;
 	heapEntryQueues[VMM_HE_UNUSED].count--;
 	return he;
 }
diff --git a/kernel/mm/vmm.h b/kernel/mm/vmm.h
index 1481c3d..13fec1c 100644
--- a/kernel/mm/vmm.h
+++ b/kernel/mm/vmm.h
@@ -27,7 +27,6 @@ typedef struct {
 	u32_t	padding;
 } __attribute__((packed)) HeapEntry_t;
 
-
 typedef struct {
 	HeapEntry_t	entry[256];	//256 HeapEntry objects = 4kb (1 page)
 } __attribute__((packed)) HeapEntryBlock_t;
@@ -37,10 +36,11 @@ typedef struct {
 	HeapEntry_t *start;
 } HeapEntryQueue_t;
 
+
 void	vmm_init();
 u32_t	vmm_map(void *virt);
-void	vmm_map1(unsigned int virt, unsigned int physical);
-void	vmm_mapn(unsigned int virt, unsigned int physical, unsigned int n);
+int	vmm_map1(unsigned int virt, unsigned int physical);
+int	vmm_mapn(unsigned int virt, unsigned int physical, unsigned int n);
 void	vmm_unmap1(unsigned int virt);
 void	vmm_unmapn(unsigned int virt, unsigned int n);
 int	vmm_map_range(void *virt_start, void *virt_end, u32_t phys_start);
diff --git a/kernel/sys/cmos.cpp b/kernel/sys/cmos.cpp
new file mode 100644
index 0000000..827f32a
--- /dev/null
+++ b/kernel/sys/cmos.cpp
@@ -0,0 +1,42 @@
+// cmos.c
+// Author: Josh Holtrop
+// Created: 02/26/04
+// Implements various CMOS function calls
+
+#include "hos_defines.h"
+#include "sys/cmos.h"
+#include "sys/io.h"
+
+//Returns the cmos type of floppy disk drive 0 (0 = not present)
+unsigned char	cmos_getfd0()
+{
+	outportb(0x70, 0x10);
+	return (inportb(0x71) >> 4);
+}
+
+
+//Returns the cmos type of floppy disk drive 1 (0 = not present)
+unsigned char	cmos_getfd1()
+{
+	outportb(0x70, 0x10);
+	return (inportb(0x71) & 0x0F);
+}
+
+
+//Returns the cmos type of hard disk drive 0 (0 = not present)
+unsigned char	cmos_gethd0()
+{
+	outportb(0x70, 0x12);
+	return (inportb(0x71) >> 4);
+}
+
+
+//Returns the cmos type of hard disk drive 1 (0 = not present)
+unsigned char	cmos_gethd1()
+{
+	outportb(0x70, 0x12);
+	return (inportb(0x71) & 0x0F);
+}
+
+
+
diff --git a/kernel/sys/cmos.h b/kernel/sys/cmos.h
new file mode 100644
index 0000000..cf5ce52
--- /dev/null
+++ b/kernel/sys/cmos.h
@@ -0,0 +1,18 @@
+// cmos.h
+// Author: Josh Holtrop
+// Created: 02/26/04
+// Implements various CMOS function calls
+
+#include "hos_defines.h"
+
+#ifndef __HOS_CMOS__
+#define __HOS_CMOS__ __HOS_CMOS__
+
+unsigned char	cmos_getfd0();
+unsigned char	cmos_getfd1();
+unsigned char	cmos_gethd0();
+unsigned char	cmos_gethd1();
+
+#endif
+
+
diff --git a/kernel/sys/io.cpp b/kernel/sys/io.cpp
new file mode 100644
index 0000000..3993d10
--- /dev/null
+++ b/kernel/sys/io.cpp
@@ -0,0 +1,8 @@
+// io.c
+// Author: Josh Holtrop
+// Created: 02/26/04
+// Implements basic port input/output functions
+
+#include "sys/io.h"
+
+
diff --git a/kernel/sys/io.h b/kernel/sys/io.h
new file mode 100644
index 0000000..b77bef1
--- /dev/null
+++ b/kernel/sys/io.h
@@ -0,0 +1,40 @@
+// io.h
+// Author: Josh Holtrop
+// Created: 02/26/04
+// Implements basic port input/output functions
+
+#ifndef __HOS_IO__
+#define __HOS_IO__ __HOS_IO__
+
+#include "hos_defines.h"
+
+//void outportb(unsigned int port, unsigned char value);
+//inline void outportw(unsigned int port, unsigned int value);
+//inline unsigned char inportb(unsigned short port);
+
+//Writes a byte out to a port
+static inline void outportb(unsigned int port, unsigned char value)		// Output a byte to a port
+{
+    asm volatile ("outb %%al,%%dx"::"d" (port), "a" (value));
+}
+
+//Writes a word out to a port
+static inline void outportw(unsigned int port, unsigned int value)		// Output a word to a port
+{
+    asm volatile ("outw %%ax,%%dx"::"d" (port), "a" (value));
+}
+
+//Reads a byte from a port
+static inline unsigned char inportb(unsigned short port)
+{
+	unsigned char ret_val;
+
+	asm volatile("inb %w1,%b0"
+		: "=a"(ret_val)
+		: "d"(port));
+	return ret_val;
+}
+
+#endif
+
+
diff --git a/kernel/sys/pic.cpp b/kernel/sys/pic.cpp
new file mode 100644
index 0000000..310ff60
--- /dev/null
+++ b/kernel/sys/pic.cpp
@@ -0,0 +1,30 @@
+// pic.c
+// Author: Josh Holtrop
+// Created: 02/26/04
+
+#include "hos_defines.h"
+#include "pic.h"
+#include "sys/io.h"
+
+//Re-maps the Programmable Interrupr Controllers so IRQ0->pic1 base address, IRG8->pic2 base address
+void pic_remap(int pic1, int pic2)
+{
+	byte	a1, a2;
+
+	a1 = inportb(PIC1_DATA);      //0x21
+	a2 = inportb(PIC2_DATA);      //0xA1
+
+	outportb(PIC1_COMMAND, ICW1_INIT+ICW1_ICW4);	//0x20, 0x10+0x01 00010001b
+	outportb(PIC2_COMMAND, ICW1_INIT+ICW1_ICW4);	//0xA0, 0x10+0x01 00010001b
+	outportb(PIC1_DATA, pic1);			//0x21, pic1
+	outportb(PIC2_DATA, pic2);			//0xA1, pic2
+	outportb(PIC1_DATA, 4);				//0x21, 0x04      00000100b
+	outportb(PIC2_DATA, 2);				//0xA1, 0x02      00000010b
+	outportb(PIC1_DATA, ICW4_8086);			//0x21, 0x01      00000001b
+	outportb(PIC2_DATA, ICW4_8086);			//0xA1, 0x01      00000001b
+
+	outportb(PIC1_DATA, a1);			//0x21
+	outportb(PIC2_DATA, a2);			//0xA1
+}
+
+
diff --git a/kernel/sys/pic.h b/kernel/sys/pic.h
new file mode 100644
index 0000000..c363732
--- /dev/null
+++ b/kernel/sys/pic.h
@@ -0,0 +1,65 @@
+// pic.h
+// Author: Josh Holtrop
+// Created: 02/26/04
+
+#ifndef __HOS_PIC__
+#define __HOS_PIC__ __HOS_PIC__
+
+#include "hos_defines.h"
+#include "sys/io.h"
+
+#define	PIC1		0x20
+#define	PIC2		0xA0
+#define	PIC1_COMMAND	PIC1
+#define	PIC1_DATA	(PIC1+1)
+#define	PIC2_COMMAND	PIC2
+#define	PIC2_DATA	(PIC2+1)
+#define	PIC_EOI		0x20
+
+#define	ICW1_ICW4	0x01		/* ICW4 (not) needed */
+#define	ICW1_SINGLE	0x02		/* Single (cascade) mode */
+#define	ICW1_INTERVAL4	0x04		/* Call address interval 4 (8) */
+#define	ICW1_LEVEL	0x08		/* Level triggered (edge) mode */
+#define	ICW1_INIT	0x10		/* Initialization - required! */
+
+#define	ICW4_8086	0x01		/* 8086/88 (MCS-80/85) mode */
+#define	ICW4_AUTO	0x02		/* Auto (normal) EOI */
+#define	ICW4_BUF_SLAVE	0x08		/* Buffered mode/slave */
+#define	ICW4_BUF_MASTER	0x0C		/* Buffered mode/master */
+#define	ICW4_SFNM	0x10		/* Special fully nested (not) */
+
+void pic_remap(int pic1, int pic2);
+//inline void pic_mask1(byte mask);
+//inline void pic_mask2(byte mask);
+//inline void pic_eoi();
+//inline void pic_eoi2();
+
+//Masks interrupts on first Programmable Interrupt Controller
+static inline void pic_mask1(byte mask)
+{
+	outportb(PIC1_DATA, mask);			//0x21, maskfield *OCW1*
+}
+
+//Masks interrupts on second Programmable Interrupt Controller
+static inline void pic_mask2(byte mask)
+{
+ 	outportb(PIC2_DATA, mask);			//0xA1, maskfield *OCW1*
+}
+
+
+//Signals an End Of Interrupt signal to the first PIC
+static inline void pic_eoi()
+{
+	outportb(0x20, 0x20);
+}
+
+//Signals an End Of Interrupt signal to both the second and first PIC unit
+static inline void pic_eoi2()
+{
+ 	outportb(0xA0, 0x20);
+ 	outportb(0x20, 0x20);
+}
+
+#endif
+
+
diff --git a/kernel/sys/rtc.cpp b/kernel/sys/rtc.cpp
new file mode 100644
index 0000000..d0cd1ad
--- /dev/null
+++ b/kernel/sys/rtc.cpp
@@ -0,0 +1,83 @@
+// rtc.c
+// Author: Josh Holtrop
+// Created: 02/26/04
+// Implements Real-Time Clock function calls
+// These functions are for reading and writing various values stored on the CMOS Real Time Clock
+// Parameters / return values are in BCD format
+
+#include "hos_defines.h"
+#include "sys/rtc.h"
+#include "sys/io.h"
+
+unsigned char	rtc_readDay()
+{
+	outportb(0x70, 7);
+	return inportb(0x71);
+}
+
+unsigned char	rtc_readMonth()
+{
+	outportb(0x70, 8);
+	return inportb(0x71);
+}
+
+unsigned char	rtc_readYear()
+{
+	outportb(0x70, 9);
+	return inportb(0x71);
+}
+
+unsigned char	rtc_readSecond()
+{
+	outportb(0x70, 0);
+	return inportb(0x71);
+}
+
+unsigned char	rtc_readMinute()
+{
+	outportb(0x70, 2);
+	return inportb(0x71);
+}
+
+unsigned char	rtc_readHour()
+{
+	outportb(0x70, 4);
+	return inportb(0x71);
+}
+
+void	rtc_setDay(unsigned char day)
+{
+	outportb(0x70, 7);
+	outportb(0x71, day);
+}
+
+void	rtc_setMonth(unsigned char month)
+{
+	outportb(0x70, 8);
+	outportb(0x71, month);
+}
+
+void	rtc_setYear(unsigned char year)
+{
+	outportb(0x70, 9);
+	outportb(0x71, year);
+}
+
+void	rtc_setSecond(unsigned char second)
+{
+	outportb(0x70, 0);
+	outportb(0x71, second);
+}
+
+void	rtc_setMinute(unsigned char minute)
+{
+	outportb(0x70, 2);
+	outportb(0x71, minute);
+}
+
+void	rtc_setHour(unsigned char hour)
+{
+	outportb(0x70, 4);
+	outportb(0x71, hour);
+}
+
diff --git a/kernel/sys/rtc.h b/kernel/sys/rtc.h
new file mode 100644
index 0000000..3c589de
--- /dev/null
+++ b/kernel/sys/rtc.h
@@ -0,0 +1,28 @@
+// rtc.h
+// Author: Josh Holtrop
+// Created: 02/26/04
+// Implements Real-Time Clock function calls
+// These functions are for reading and writing various values stored on the CMOS Real Time Clock
+// Parameters / return values are in BCD format
+
+#ifndef __HOS_RTC__
+#define __HOS_RTC__ __HOS_RTC__
+
+#include "hos_defines.h"
+
+unsigned char	rtc_readDay();
+unsigned char	rtc_readMonth();
+unsigned char	rtc_readYear();
+unsigned char	rtc_readSecond();
+unsigned char	rtc_readMinute();
+unsigned char	rtc_readHour();
+void	rtc_setDay(unsigned char dat);
+void	rtc_setMonth(unsigned char month);
+void	rtc_setYear(unsigned char year);
+void	rtc_setSecond(unsigned char second);
+void	rtc_setMinute(unsigned char minute);
+void	rtc_setHour(unsigned char hour);
+
+#endif
+
+