diff --git a/csim.c b/csim.c
index 1e7d8ef..7c5102b 100644
--- a/csim.c
+++ b/csim.c
@@ -14,6 +14,10 @@
    0 - success
    1 - usage error
    -1 - file error
+
+   @TODO Rename block_bits to block_offset_bits.
+   @TODO Fix format
+   @TODO Fix casts of parse_int_arg in main to int rather than uint8_t.
 */
 
 /**** Headers ****/
@@ -196,10 +200,11 @@ void bad_usage_error(void)
 }
 
 /**
-   Parses a string into a size_t.
+   Parses a string into a an positive integer; error if not possible.
    @param arg The string to parse.
    @param opt The option being parsed. If 'E', the output can not be 0.
-   @return The parsed long integer if the argument was an integer.
+          Otherwise, used only for helpful error messages.
+   @return The parsed long integer if the argument was valid .
    @note Exits if argument is invalid.
  */
 long parse_int_arg(char* arg, char opt)
@@ -221,21 +226,29 @@ long parse_int_arg(char* arg, char opt)
 /**
    Calculates a size using a given number of bits.
    @param bits The power of 2 to use.
-   @note Exits if number of bits is larger than a size_t.
+   @return 2^bits if it does not overflow.
+   @note Exits if number of bits is larger than a signed int.
+   @TODO Fix format string to ints.
  */
 long bits_to_size(int bits)
 {
-	int max_shift = 8*sizeof(int);
+	int max_shift = 8*sizeof(int)-1;
 	if (bits > max_shift-1) {
 		printf("Argument %hhd too large (-s and -b must be less than %hhd)", bits, max_shift);
 		exit(1);
 	}
-	return (size_t)1 << bits;
+	return (long)1 << bits;
 }
 
 
 /***************************** SUB-MAIN FUNCTIONS *****************************/
 
+/**
+   Increments the cgiven ache operation counters based on the given result code.
+   @param result The cache operation result code to parse (H, M, or E).
+   @param score The score struct to increment.
+   @TODO Fix this into a total of 3 conditionals.
+ */
 void increment_result_counters(char result, results* score)
 {
 	score->hits += (result == 'H');
@@ -250,6 +263,12 @@ void increment_result_counters(char result, results* score)
 
 /********************* CACHE CREATION/DELETION FUNCTIONS  *********************/
 
+/**
+   @param num_sets The number of sets in the cache.
+   @param num_lines The number of lines in each set.
+   @return A pointer to the allocated cache's set list.
+   @TODO Handle cases where not enough space can be allocated.
+ */
 linked_line** make_cache(long num_sets, long num_lines)
 {
 	linked_line** cache = (linked_line**)calloc(num_sets, sizeof(linked_line*));
@@ -279,6 +298,10 @@ linked_line* make_set(linked_line* newer, long num_lines) {
 	return current;
 }
 
+/**
+   @param cache A pointer to the cache to free.
+   @param num_sets The number of sets in the cache.
+ */
 void free_cache(linked_line** cache, long num_sets)
 {
 	int ii;
@@ -302,6 +325,10 @@ void free_set(linked_line* line) {
 
 /************************** CACHE VIEWING FUNCTIONS  **************************/
 
+/**
+   @cache The cache to print.
+   @cache num_sets The number of sets in the cache.
+ */
 void print_cache(linked_line** cache, long num_sets)
 {
 	int ii;
@@ -310,6 +337,12 @@ void print_cache(linked_line** cache, long num_sets)
 	}
 }
 
+/**
+   Prints a cache line and all lines modified less recently than it in its set.<br />
+   The format is: <br />
+   address validity.tag		address of newer:address of older
+   @param line The set/line to print, or NULL. If null, does nothing.
+ */
 void print_set(linked_line* line)
 {
 	if (line != NULL) {
@@ -323,6 +356,19 @@ void print_set(linked_line* line)
 
 /*************************** CACHE ACCESS FUNCTIONS ***************************/
 
+/**
+   Simulates a cache access operation.
+   @param cache The cache to access.
+   @param address The address to access in the cache.
+   @param set_bits The number of set bits in the address.
+   @param block_bits The number of block offset bits in the address.
+   @param num_lines The number of lines per set.
+   @return 'H' if a hit, 'M' if a miss, 'E' if a miss and eviction
+
+   @TODO Pass set and tag into cache_access instead of an address and sizes.
+   @TODO Make the tag and set retrieval a function?
+   @TODO Make the re-linking of the set into its own function.
+ */
 char cache_access(linked_line** cache, long address,
 				  int set_bits, int block_bits, long num_lines)
 {
@@ -353,8 +399,13 @@ char cache_access(linked_line** cache, long address,
 }
 
 /**
-   @returns the first line with a matching tag, the first invalid line,
-   or the first line without an older (i.e. the end of the set
+   Finds a line in the given set that holds the given tag, or the least-recently
+   used line if the tag is not in the set, or the next invalid line if not all
+   of the lines have been used.
+   @param line Initially, the most-recently-used line in the set. In the
+               recursion, iterates through the lines in the set.
+   @returns The first line with a matching tag, the first invalid line,
+            or the first line without an older (i.e. the end of the set).
  */
 linked_line* find_line(linked_line* line, long tag)
 {