Move hack-as up one directory

6 files changed, 0 insertions, 1007 deletions

diff --git a/projects/06/hack-as/hack-as.c b/projects/06/hack-as/hack-as.c
deleted file mode 100644
index b152fb8..0000000
--- a/projects/06/hack-as/hack-as.c
+++ /dev/null
@@ -1,384 +0,0 @@
-#include <stdlib.h>
-#include <stdio.h>
-#include <stdint.h>
-#include <stdbool.h>
-#include <string.h>
-
-#define MAX_ASM_LINE_LEN	64
-#define INST_CHUNK_LEN		64
-#define MAX_INST_LEN		32768
-#define MAX_ADDR		32767
-
-#define EXIT_CODE_FILE_ERROR	1
-#define EXIT_CODE_ILLEGAL_CHAR	2
-#define EXIT_CODE_SIZE_EXCEEDED	3
-#define EXIT_CODE_SYNTAX_ERROR	4
-#define EXIT_CODE_ADDR_ERROR	5
-
-struct symbol {
-	char *label;
-	int addr;
-};
-
-char find_illegal_symbol_char(char *symbol) {
-	// symbol should not begin with number
-	// nand2tetris implementation allows it, but the standard says otherwise
-	if (*symbol >= '0' && *symbol <= '9') return *symbol;
-	for (char *c = symbol; *c != '\0'; c++) {
-		if (!((*c >= 'A' && *c <= 'Z') || (*c >= 'a' && *c <= 'z')
-			|| (*c >= '0' && *c <= '9')
-			|| *c == '_' || *c == '.' || *c == '$' || *c == ':')
-		) {
-			return *c;
-		}
-	}
-	return -1;
-}
-
-void print_symbols(struct symbol *symbols, int cnt) {
-	printf("====== SYMBOLS =====\nlabel\taddr\n");
-	for (int i = 0; i < cnt; i++) {
-		printf("%s\t%d\n", symbols[i].label, symbols[i].addr);
-	}
-}
-
-void print_binary_and_asm(uint16_t *binary, char **asm_lines, int cnt) {
-	printf("\n====== RESULTS =====\naddr\tbinary          \tinst\n");
-	for (int i = 0; i < cnt; i++) {
-		char binary_str[17];
-		binary_str[16] = '\0';
-		for (int b = 0; b < 16; b++) {
-			binary_str[b] = '0' + (*(binary + i) >> (15 - b)) % 2;
-		}
-		printf("%d\t%s\t%s\n", i, binary_str, asm_lines[i]);
-	}
-}
-
-void write_binary(FILE *file, uint16_t *binary, int cnt) {
-	for (int i = 0; i < cnt; i++) {
-		char binary_str[17];
-		binary_str[16] = '\0';
-		for (int b = 0; b < 16; b++) {
-			binary_str[b] = '0' + (*(binary + i) >> (15 - b)) % 2;
-		}
-		fprintf(file, "%s\n", binary_str);
-	}
-}
-
-uint16_t assemble_inst(char *asm_line) {
-	// assemble one line of assembly, terminated with \0
-	// labels and variables must be replaced with corresponding addresses beforehand
-	uint16_t inst = 0;
-	if (*asm_line == '@') {
-		// A instruction
-		char *addr_str = asm_line + 1;
-		int addr = atoi(addr_str);
-		if (addr < 0 || addr > MAX_ADDR) {
-			fprintf(stderr, "Address out of range: %d\n", addr);
-			exit(EXIT_CODE_ADDR_ERROR);
-		}
-		inst = (uint16_t) addr;
-	} else {
-		// C instruction
-		inst = 0xe000;	// set 3 MSBs to 1
-		char *eq = asm_line;
-		for (char *c = asm_line; *c != '\0'; c++) {
-			// find first equal sign (eq == asm_line if not found)
-			if (*c == '=') {
-				eq = c;
-				break;
-			}
-		}
-
-		// slice out destination and copy to dest
-		int dest_len = eq - asm_line;
-		char *dest = malloc(dest_len + 1);
-		strncpy(dest, asm_line, dest_len);
-		dest[dest_len] = '\0';
-		if (dest_len == 0) {}	// ignore
-		else if (strcmp(dest, "M") == 0)	inst |= 0b001 << 3;
-		else if (strcmp(dest, "D") == 0)	inst |= 0b010 << 3;
-		else if (strcmp(dest, "MD") == 0)	inst |= 0b011 << 3;
-		else if (strcmp(dest, "A") == 0)	inst |= 0b100 << 3;
-		else if (strcmp(dest, "AM") == 0)	inst |= 0b101 << 3;
-		else if (strcmp(dest, "AD") == 0)	inst |= 0b110 << 3;
-		else if (strcmp(dest, "AMD") == 0)	inst |= 0b111 << 3;
-		else {
-			fprintf(stderr, "Invalid destination: %s\n", dest);
-			exit(EXIT_CODE_SYNTAX_ERROR);
-		}
-		free(dest);
-
-		char *semi = eq;
-		for (; *semi != '\0'; semi++) {
-			// find jump instruction after semicolon (;) (*semi == '\0' if not found)
-			if (*semi == ';') break;
-		}
-		// ignore if there's no semicolon, or there's nothing after it
-		if (*semi == '\0' || *(semi + 1) == '\0') {}
-		else if (strcmp(semi + 1, "JGT") == 0)	inst |= 0b001;
-		else if (strcmp(semi + 1, "JEQ") == 0)	inst |= 0b010;
-		else if (strcmp(semi + 1, "JGE") == 0)	inst |= 0b011;
-		else if (strcmp(semi + 1, "JLT") == 0)	inst |= 0b100;
-		else if (strcmp(semi + 1, "JNE") == 0)	inst |= 0b101;
-		else if (strcmp(semi + 1, "JLE") == 0)	inst |= 0b110;
-		else if (strcmp(semi + 1, "JMP") == 0)	inst |= 0b111;
-		else {
-			fprintf(stderr, "Invalid jump instruction: %s\n", semi + 1);
-			exit(EXIT_CODE_SYNTAX_ERROR);
-		}
-
-		// slice out computation and copy to comp
-		int comp_len = (*eq == '=') ? (semi - eq - 1) : (semi - eq);
-		char *comp = malloc(comp_len + 1);
-		strncpy(comp, (*eq == '=') ? (eq + 1) : eq, comp_len);
-		comp[comp_len] = '\0';
-		if (strcmp(comp, "0") == 0)		inst |= 0b0101010 << 6;
-		else if (strcmp(comp, "1") == 0)	inst |= 0b0111111 << 6;
-		else if (strcmp(comp, "-1") == 0)	inst |= 0b0111010 << 6;
-		else if (strcmp(comp, "D") == 0)	inst |= 0b0001100 << 6;
-		else if (strcmp(comp, "A") == 0)	inst |= 0b0110000 << 6;
-		else if (strcmp(comp, "M") == 0)	inst |= 0b1110000 << 6;
-		else if (strcmp(comp, "!D") == 0)	inst |= 0b0001101 << 6;
-		else if (strcmp(comp, "!A") == 0)	inst |= 0b0110001 << 6;
-		else if (strcmp(comp, "!M") == 0)	inst |= 0b1110001 << 6;
-		else if (strcmp(comp, "-D") == 0)	inst |= 0b0001111 << 6;
-		else if (strcmp(comp, "-A") == 0)	inst |= 0b0110011 << 6;
-		else if (strcmp(comp, "-M") == 0)	inst |= 0b1110011 << 6;
-		else if (strcmp(comp, "D+1") == 0)	inst |= 0b0011111 << 6;
-		else if (strcmp(comp, "A+1") == 0)	inst |= 0b0110111 << 6;
-		else if (strcmp(comp, "M+1") == 0)	inst |= 0b1110111 << 6;
-		else if (strcmp(comp, "D-1") == 0)	inst |= 0b0001110 << 6;
-		else if (strcmp(comp, "A-1") == 0)	inst |= 0b0110010 << 6;
-		else if (strcmp(comp, "M-1") == 0)	inst |= 0b1110010 << 6;
-		else if (strcmp(comp, "D+A") == 0
-			|| strcmp(comp, "A+D") == 0)	inst |= 0b0000010 << 6;
-		else if (strcmp(comp, "D+M") == 0
-			|| strcmp(comp, "M+D") == 0)	inst |= 0b1000010 << 6;
-		else if (strcmp(comp, "D-A") == 0)	inst |= 0b0010011 << 6;
-		else if (strcmp(comp, "D-M") == 0)	inst |= 0b1010011 << 6;
-		else if (strcmp(comp, "A-D") == 0)	inst |= 0b0000111 << 6;
-		else if (strcmp(comp, "M-D") == 0)	inst |= 0b1000111 << 6;
-		else if (strcmp(comp, "D&A") == 0
-			|| strcmp(comp, "A&D") == 0)	inst |= 0b0000000 << 6;
-		else if (strcmp(comp, "D&M") == 0
-			|| strcmp(comp, "M&D") == 0)	inst |= 0b1000000 << 6;
-		else if (strcmp(comp, "D|A") == 0
-			|| strcmp(comp, "A|D") == 0)	inst |= 0b0010101 << 6;
-		else if (strcmp(comp, "D|M") == 0
-			|| strcmp(comp, "M|D") == 0)	inst |= 0b1010101 << 6;
-		else {
-			fprintf(stderr, "Invalid computation: %s\n", comp);
-			exit(EXIT_CODE_SYNTAX_ERROR);
-		}
-		free(comp);
-	}
-	return inst;
-}
-
-size_t assembler(char *input_fn, bool verbose) {
-	// open input file
-	FILE *input_file = fopen(input_fn, "r");
-	if (input_file == NULL) {
-		fprintf(stderr, "Cannot open input file: %s\n", input_fn);
-		exit(EXIT_CODE_FILE_ERROR);
-	}
-	// find size of input file
-	fseek(input_file, 0, SEEK_END);
-	size_t file_size = ftell(input_file);
-	fseek(input_file, 0, SEEK_SET);
-	// read input file
-	char *file_content = malloc(file_size);
-	fread(file_content, file_size, 1, input_file);
-	fclose(input_file);
-	
-	// strip away comments, labels, blank lines and whitespace from file_content
-	// resulting in lines of what looks like instructions in assembly but is not necessarily correct
-	// labels in parentheses are assigned corresponding addresses in ROM, then collected in `symbols`
-	// the strings are scattered in the heap but asm_lines collects pointers to them
-	char **asm_lines = calloc(INST_CHUNK_LEN, sizeof(char*));
-	int asm_line_cnt = 0;	// no. of lines (metaphorically) written into asm_lines
-	char *asm_line = malloc(MAX_ASM_LINE_LEN + 1);	// one line of (probably) assembly
-	int asm_char_cnt = 0;		// no. of chars written into asm_line
-	struct symbol symbols[MAX_INST_LEN] = {
-		{"SP", 0}, {"LCL", 1}, {"ARG", 2}, {"THIS", 3}, {"THAT", 4},
-		{"R0", 0}, {"R1", 1}, {"R2", 2}, {"R3", 3},
-		{"R4", 4}, {"R5", 5}, {"R6", 6}, {"R7", 7},
-		{"R8", 8}, {"R9", 9}, {"R10", 10}, {"R11", 11},
-		{"R12", 12}, {"R13", 13}, {"R14", 14}, {"R15", 15},
-		{"SCREEN", 16384}, {"KBD", 24576},
-	};
-	const int predef_symbol_cnt = 23;	// no. of predefined symbols
-	int user_symbol_cnt = 0;
-	for (size_t i = 0; i < file_size; i++) {
-		switch (file_content[i]) {
-		case '\n':
-			// end of line; try to figure out what's in asm_line
-			if (asm_char_cnt == 0) continue;	// skip blank line or comment line
-			*(asm_line + asm_char_cnt) = '\0';
-			if (*asm_line == '(' && *(asm_line + asm_char_cnt - 1) == ')') {
-				// this line may be a label; extract label from between the parentheses
-				char *label = malloc(asm_char_cnt - 1);
-				strncpy(label, asm_line + 1, asm_char_cnt - 2);
-				free(asm_line);
-				*(label + asm_char_cnt - 2) = '\0';
-				char illegal_char = find_illegal_symbol_char(label);
-				if (illegal_char != -1) {
-					fprintf(stderr, "Illegal character: %c\n", illegal_char);
-					exit(EXIT_CODE_ILLEGAL_CHAR);
-				}
-				// TODO: error on repeated label
-				symbols[predef_symbol_cnt + user_symbol_cnt] = (struct symbol) {label, asm_line_cnt};
-				user_symbol_cnt++;
-			} else {
-				// this line may be an instruction
-				// if we used up a chunk, realloc asm_lines
-				if (asm_line_cnt > 0 && asm_line_cnt % INST_CHUNK_LEN == 0) {
-					asm_lines = realloc(asm_lines, (asm_line_cnt + INST_CHUNK_LEN) * sizeof(char*));
-				}
-				asm_lines[asm_line_cnt] = asm_line;
-				asm_line_cnt++;
-			}
-			// allocate memory for next line
-			asm_char_cnt = 0;
-			asm_line = malloc(MAX_ASM_LINE_LEN + 1);
-			break;
-		case '/':
-			if (i + 1 < file_size && file_content[i + 1] == '/') {
-				// we encountered a comment
-				// skip to last char of line
-				while (i + 1 < file_size && file_content[i + 1] != '\n') i++;
-			} else {
-				fprintf(stderr, "Illegal character: /\n");
-				exit(EXIT_CODE_ILLEGAL_CHAR);
-			}
-			break;
-		case ' ':
-		case '\t':
-		case '\r':
-			break;	// ignore whitespace and CR
-		default:
-			*(asm_line + asm_char_cnt) = file_content[i];
-			asm_char_cnt++;
-			if (asm_char_cnt > MAX_ASM_LINE_LEN) {
-				fprintf(stderr, "Max assembly line length (%d) exceeded\n", MAX_ASM_LINE_LEN);
-				exit(EXIT_CODE_SIZE_EXCEEDED);
-			}
-		}
-	}
-	free(asm_line);
-	free(file_content);
-
-	// find and assign address to variables on the fly
-	int addr = 16;	// variable addresses start at 16
-	for (int i = 0; i < asm_line_cnt; i++) {
-		if (asm_lines[i] == NULL) break;	// no more instructions
-		if (*(asm_lines[i]) != '@') continue;	// not an A-instruction
-		char *addr_str = malloc(strlen(asm_lines[i]));
-		strcpy(addr_str, asm_lines[i] + 1);	// whatever comes after the @
-		if (strlen(addr_str) == 0) {
-			fprintf(stderr, "Address cannot be empty\n");
-			exit(EXIT_CODE_SYNTAX_ERROR);
-		}
-		bool is_symbol = false;
-		for (char *c = addr_str; *c != '\0'; c++) {
-			// search for non-numeric chars in addr_str
-			if (*c < '0' || *c > '9') {
-				is_symbol = true;
-			}
-		}
-		if (!is_symbol) {
-			free(addr_str);
-			continue;	// address is decimal constant
-		}
-		char illegal_char = find_illegal_symbol_char(addr_str);
-		if (illegal_char != -1) {
-			fprintf(stderr, "Illegal character: %c\n", illegal_char);
-			exit(EXIT_CODE_ILLEGAL_CHAR);
-		}
-		// search for symbol in list
-		bool found = false;
-		for (int s = 0; s < predef_symbol_cnt + user_symbol_cnt; s++) {
-			if (strcmp(addr_str, symbols[s].label) == 0) {
-				// overwrite asm line with decimal constant
-				sprintf(asm_lines[i], "@%d", symbols[s].addr);
-				found = true;
-				free(addr_str);
-				break;
-			}
-		}
-		if (!found) {
-			// add symbol to list
-			symbols[predef_symbol_cnt + user_symbol_cnt] = (struct symbol) {addr_str, addr};
-			sprintf(asm_lines[i], "@%d", addr);
-			user_symbol_cnt++;
-			addr++;
-		}
-	}
-	
-	// start assembling
-	uint16_t *binary = calloc(32768, 2);
-	size_t inst_cnt = 0;	// current no. of instructions in binary
-	for (char **line = asm_lines; *line != NULL; line++) {
-		*(binary + inst_cnt) = assemble_inst(*line);
-		inst_cnt++;
-		if (inst_cnt > MAX_INST_LEN) {
-			fprintf(stderr, "Max number of instruction (%d) exceeded\n", MAX_INST_LEN);
-			exit(EXIT_CODE_SIZE_EXCEEDED);
-		}
-	}
-
-	if (verbose) {
-		print_symbols(symbols + predef_symbol_cnt, user_symbol_cnt);
-		print_binary_and_asm(binary, asm_lines, inst_cnt);
-		printf("\n");
-	}
-
-	for (char **line = asm_lines; *line != NULL; line++) free(*line);
-	free(asm_lines);
-	for (int s = predef_symbol_cnt; s < predef_symbol_cnt + user_symbol_cnt; s++) {
-		free(symbols[s].label);
-	}
-
-	// write binary
-	// output_fn = input_fn[:-4] + ".hack" if input_fn.endswith(".asm") else input_fn + ".hack"
-	int input_fn_len = strlen(input_fn);
-	char *output_fn = malloc(input_fn_len + 6);
-	strcpy(output_fn, input_fn);
-	if (input_fn_len >= 4 && strcmp(input_fn + input_fn_len - 4, ".asm") == 0) {
-		sprintf(output_fn + input_fn_len - 4, ".hack");
-	} else {
-		sprintf(output_fn + input_fn_len, ".hack");
-	}
-
-	FILE *output_file = fopen(output_fn, "w");
-	if (output_file == NULL) {
-		fprintf(stderr, "Cannot open output file: %s\n", output_fn);
-		exit(EXIT_CODE_FILE_ERROR);
-	}
-	write_binary(output_file, binary, inst_cnt);
-	fclose(output_file);
-	free(binary);
-	printf("Binary written to %s\n", output_fn);
-	free(output_fn);
-
-	return inst_cnt;
-}
-
-int main(int argc, char *argv[]) {
-	char *input_fn = NULL;
-	bool verbose = false;
-	for (int i = 1; i < argc; i++) {
-		if (strcmp(argv[i], "-h") == 0) {
-			printf("Usage: %s <input.asm> [-v]\n-v -- verbose mode\n", argv[0]);
-			exit(0);
-		} else if (strcmp(argv[i], "-v") == 0) {
-			verbose = true;
-		} else {
-			input_fn = argv[i];
-		}
-	}
-
-	assembler(input_fn, verbose);
-	return 0;
-}
diff --git a/projects/06/hack-as/hack-as.min.c b/projects/06/hack-as/hack-as.min.c
deleted file mode 100644
index 5d7252f..0000000
--- a/projects/06/hack-as/hack-as.min.c
+++ /dev/null
@@ -1,268 +0,0 @@
-#include <stdlib.h>
-#include <stdio.h>
-#include <stdint.h>
-#include <stdbool.h>
-#include <string.h>
-
-#define MAX_ASM_LINE_LEN	64
-#define INST_CHUNK_LEN		64
-#define MAX_INST_LEN		32768
-#define MAX_ADDR		32767
-
-struct symbol {
-	char *label;
-	int addr;
-};
-
-void write_binary(FILE *file, uint16_t *binary, int cnt) {
-	for (int i = 0; i < cnt; i++) {
-		char binary_str[17];
-		binary_str[16] = '\0';
-		for (int b = 0; b < 16; b++) {
-			binary_str[b] = '0' + (*(binary + i) >> (15 - b)) % 2;
-		}
-		fprintf(file, "%s\n", binary_str);
-	}
-}
-
-uint16_t assemble_inst(char *asm_line) {
-	// assemble one line of assembly, terminated with \0
-	// labels and variables must be replaced with corresponding addresses beforehand
-	if (*asm_line == '@') {
-		// A instruction
-		return atoi(asm_line + 1);
-	} else {
-		// C instruction
-		uint16_t inst = 0xe000;	// set 3 MSBs to 1
-		char *eq = asm_line;
-		for (char *c = asm_line; *c != '\0'; c++) {
-			// find first equal sign (eq == asm_line if not found)
-			if (*c == '=') {
-				eq = c;
-				break;
-			}
-		}
-
-		// slice out destination and copy to dest
-		int dest_len = eq - asm_line;
-		char *dest = malloc(dest_len + 1);
-		strncpy(dest, asm_line, dest_len);
-		dest[dest_len] = '\0';
-		if (dest_len == 0) {}	// ignore
-		else if (strcmp(dest, "M") == 0)	inst |= 0b001 << 3;
-		else if (strcmp(dest, "D") == 0)	inst |= 0b010 << 3;
-		else if (strcmp(dest, "MD") == 0)	inst |= 0b011 << 3;
-		else if (strcmp(dest, "A") == 0)	inst |= 0b100 << 3;
-		else if (strcmp(dest, "AM") == 0)	inst |= 0b101 << 3;
-		else if (strcmp(dest, "AD") == 0)	inst |= 0b110 << 3;
-		else if (strcmp(dest, "AMD") == 0)	inst |= 0b111 << 3;
-		free(dest);
-
-		char *semi = eq;
-		for (; *semi != '\0'; semi++) {
-			// find jump instruction after semicolon (;) (*semi == '\0' if not found)
-			if (*semi == ';') break;
-		}
-		// ignore if there's no semicolon, or there's nothing after it
-		if (*semi == '\0' || *(semi + 1) == '\0') {}
-		else if (strcmp(semi + 1, "JGT") == 0)	inst |= 0b001;
-		else if (strcmp(semi + 1, "JEQ") == 0)	inst |= 0b010;
-		else if (strcmp(semi + 1, "JGE") == 0)	inst |= 0b011;
-		else if (strcmp(semi + 1, "JLT") == 0)	inst |= 0b100;
-		else if (strcmp(semi + 1, "JNE") == 0)	inst |= 0b101;
-		else if (strcmp(semi + 1, "JLE") == 0)	inst |= 0b110;
-		else if (strcmp(semi + 1, "JMP") == 0)	inst |= 0b111;
-
-		// slice out computation and copy to comp
-		int comp_len = (*eq == '=') ? (semi - eq - 1) : (semi - eq);
-		char *comp = malloc(comp_len + 1);
-		strncpy(comp, (*eq == '=') ? (eq + 1) : eq, comp_len);
-		comp[comp_len] = '\0';
-		if (strcmp(comp, "0") == 0)		inst |= 0b0101010 << 6;
-		else if (strcmp(comp, "1") == 0)	inst |= 0b0111111 << 6;
-		else if (strcmp(comp, "-1") == 0)	inst |= 0b0111010 << 6;
-		else if (strcmp(comp, "D") == 0)	inst |= 0b0001100 << 6;
-		else if (strcmp(comp, "A") == 0)	inst |= 0b0110000 << 6;
-		else if (strcmp(comp, "M") == 0)	inst |= 0b1110000 << 6;
-		else if (strcmp(comp, "!D") == 0)	inst |= 0b0001101 << 6;
-		else if (strcmp(comp, "!A") == 0)	inst |= 0b0110001 << 6;
-		else if (strcmp(comp, "!M") == 0)	inst |= 0b1110001 << 6;
-		else if (strcmp(comp, "-D") == 0)	inst |= 0b0001111 << 6;
-		else if (strcmp(comp, "-A") == 0)	inst |= 0b0110011 << 6;
-		else if (strcmp(comp, "-M") == 0)	inst |= 0b1110011 << 6;
-		else if (strcmp(comp, "D+1") == 0)	inst |= 0b0011111 << 6;
-		else if (strcmp(comp, "A+1") == 0)	inst |= 0b0110111 << 6;
-		else if (strcmp(comp, "M+1") == 0)	inst |= 0b1110111 << 6;
-		else if (strcmp(comp, "D-1") == 0)	inst |= 0b0001110 << 6;
-		else if (strcmp(comp, "A-1") == 0)	inst |= 0b0110010 << 6;
-		else if (strcmp(comp, "M-1") == 0)	inst |= 0b1110010 << 6;
-		else if (strcmp(comp, "D+A") == 0
-			|| strcmp(comp, "A+D") == 0)	inst |= 0b0000010 << 6;
-		else if (strcmp(comp, "D+M") == 0
-			|| strcmp(comp, "M+D") == 0)	inst |= 0b1000010 << 6;
-		else if (strcmp(comp, "D-A") == 0)	inst |= 0b0010011 << 6;
-		else if (strcmp(comp, "D-M") == 0)	inst |= 0b1010011 << 6;
-		else if (strcmp(comp, "A-D") == 0)	inst |= 0b0000111 << 6;
-		else if (strcmp(comp, "M-D") == 0)	inst |= 0b1000111 << 6;
-		else if (strcmp(comp, "D&A") == 0
-			|| strcmp(comp, "A&D") == 0)	inst |= 0b0000000 << 6;
-		else if (strcmp(comp, "D&M") == 0
-			|| strcmp(comp, "M&D") == 0)	inst |= 0b1000000 << 6;
-		else if (strcmp(comp, "D|A") == 0
-			|| strcmp(comp, "A|D") == 0)	inst |= 0b0010101 << 6;
-		else if (strcmp(comp, "D|M") == 0
-			|| strcmp(comp, "M|D") == 0)	inst |= 0b1010101 << 6;
-		free(comp);
-		return inst;
-	}
-}
-
-size_t assembler(char *input_fn) {
-	// open input file
-	FILE *input_file = fopen(input_fn, "r");
-	// find size of input file
-	fseek(input_file, 0, SEEK_END);
-	size_t file_size = ftell(input_file);
-	fseek(input_file, 0, SEEK_SET);
-	// read input file
-	char *file_content = malloc(file_size);
-	fread(file_content, file_size, 1, input_file);
-	fclose(input_file);
-	
-	// strip away comments, labels, blank lines and whitespace from file_content
-	// resulting in lines of what looks like instructions in assembly but is not necessarily correct
-	// labels in parentheses are assigned corresponding addresses in ROM, then collected in `symbols`
-	// the strings are scattered in the heap but asm_lines collects pointers to them
-	char **asm_lines = calloc(INST_CHUNK_LEN, sizeof(char*));
-	int asm_line_cnt = 0;	// no. of lines (metaphorically) written into asm_lines
-	char *asm_line = malloc(MAX_ASM_LINE_LEN + 1);	// one line of (probably) assembly
-	int asm_char_cnt = 0;		// no. of chars written into asm_line
-	struct symbol symbols[MAX_INST_LEN] = {
-		{"SP", 0}, {"LCL", 1}, {"ARG", 2}, {"THIS", 3}, {"THAT", 4},
-		{"R0", 0}, {"R1", 1}, {"R2", 2}, {"R3", 3},
-		{"R4", 4}, {"R5", 5}, {"R6", 6}, {"R7", 7},
-		{"R8", 8}, {"R9", 9}, {"R10", 10}, {"R11", 11},
-		{"R12", 12}, {"R13", 13}, {"R14", 14}, {"R15", 15},
-		{"SCREEN", 16384}, {"KBD", 24576},
-	};
-	const int predef_symbol_cnt = 23;	// no. of predefined symbols
-	int user_symbol_cnt = 0;
-	for (size_t i = 0; i < file_size; i++) {
-		switch (file_content[i]) {
-		case '\n':
-			// end of line; try to figure out what's in asm_line
-			if (asm_char_cnt == 0) continue;	// skip blank line or comment line
-			*(asm_line + asm_char_cnt) = '\0';
-			if (*asm_line == '(' && *(asm_line + asm_char_cnt - 1) == ')') {
-				// this line may be a label; extract label from between the parentheses
-				char *label = malloc(asm_char_cnt - 1);
-				strncpy(label, asm_line + 1, asm_char_cnt - 2);
-				free(asm_line);
-				*(label + asm_char_cnt - 2) = '\0';
-				symbols[predef_symbol_cnt + user_symbol_cnt] = (struct symbol) {label, asm_line_cnt};
-				user_symbol_cnt++;
-			} else {
-				// this line may be an instruction
-				// if we used up a chunk, realloc asm_lines
-				if (asm_line_cnt > 0 && asm_line_cnt % INST_CHUNK_LEN == 0) {
-					asm_lines = realloc(asm_lines, (asm_line_cnt + INST_CHUNK_LEN) * sizeof(char*));
-				}
-				asm_lines[asm_line_cnt] = asm_line;
-				asm_line_cnt++;
-			}
-			// allocate memory for next line
-			asm_char_cnt = 0;
-			asm_line = malloc(MAX_ASM_LINE_LEN + 1);
-			break;
-		case '/':
-			// we encountered a comment
-			// skip to last char of line
-			while (i + 1 < file_size && file_content[i + 1] != '\n') i++;
-			break;
-		case ' ':
-		case '\t':
-		case '\r':
-			break;	// ignore whitespace and CR
-		default:
-			*(asm_line + asm_char_cnt) = file_content[i];
-			asm_char_cnt++;
-		}
-	}
-	free(asm_line);
-	free(file_content);
-
-	// find and assign address to variables on the fly
-	int addr = 16;	// variable addresses start at 16
-	for (int i = 0; i < asm_line_cnt; i++) {
-		if (asm_lines[i] == NULL) break;	// no more instructions
-		if (*(asm_lines[i]) != '@') continue;	// not an A-instruction
-		char *addr_str = malloc(strlen(asm_lines[i]));
-		strcpy(addr_str, asm_lines[i] + 1);	// whatever comes after the @
-		bool is_symbol = false;
-		for (char *c = addr_str; *c != '\0'; c++) {
-			// search for non-numeric chars in addr_str
-			if (*c < '0' || *c > '9') is_symbol = true;
-		}
-		if (!is_symbol) {
-			free(addr_str);
-			continue;	// address is decimal constant
-		}
-		// search for symbol in list
-		bool found = false;
-		for (int s = 0; s < predef_symbol_cnt + user_symbol_cnt; s++) {
-			if (strcmp(addr_str, symbols[s].label) == 0) {
-				// overwrite asm line with decimal constant
-				sprintf(asm_lines[i], "@%d", symbols[s].addr);
-				found = true;
-				free(addr_str);
-				break;
-			}
-		}
-		if (!found) {
-			// add symbol to list
-			symbols[predef_symbol_cnt + user_symbol_cnt] = (struct symbol) {addr_str, addr};
-			sprintf(asm_lines[i], "@%d", addr);
-			user_symbol_cnt++;
-			addr++;
-		}
-	}
-	
-	// start assembling
-	uint16_t *binary = calloc(32768, 2);
-	size_t inst_cnt = 0;	// current no. of instructions in binary
-	for (char **line = asm_lines; *line != NULL; line++) {
-		*(binary + inst_cnt) = assemble_inst(*line);
-		inst_cnt++;
-	}
-
-	for (char **line = asm_lines; *line != NULL; line++) free(*line);
-	free(asm_lines);
-	for (int s = predef_symbol_cnt; s < predef_symbol_cnt + user_symbol_cnt; s++) {
-		free(symbols[s].label);
-	}
-
-	// write binary
-	// output_fn = input_fn[:-4] + ".hack" if input_fn.endswith(".asm") else input_fn + ".hack"
-	int input_fn_len = strlen(input_fn);
-	char *output_fn = malloc(input_fn_len + 6);
-	strcpy(output_fn, input_fn);
-	if (input_fn_len >= 4 && strcmp(input_fn + input_fn_len - 4, ".asm") == 0) {
-		sprintf(output_fn + input_fn_len - 4, ".hack");
-	} else {
-		sprintf(output_fn + input_fn_len, ".hack");
-	}
-
-	FILE *output_file = fopen(output_fn, "w");
-	write_binary(output_file, binary, inst_cnt);
-	fclose(output_file);
-	free(binary);
-	printf("Binary written to %s\n", output_fn);
-	free(output_fn);
-
-	return inst_cnt;
-}
-
-int main(int argc, char *argv[]) {
-	assembler(argv[1]);
-	return 0;
-}
diff --git a/projects/06/hack-as/hack-as.py b/projects/06/hack-as/hack-as.py
deleted file mode 100644
index bb70abc..0000000
--- a/projects/06/hack-as/hack-as.py
+++ /dev/null
@@ -1,269 +0,0 @@
-from sys import stderr
-from argparse import ArgumentParser
-
-EXIT_CODES = {
-    "file_error": 1,
-    "illegal_char": 2,
-    "size_exceeded": 3,
-    "syntax_error": 4,
-    "addr_error": 5,
-    "symbol_error": 6,
-}
-
-PREDEFINED_SYMBOL_CNT = 23
-MAX_INST_LEN = 32768
-MAX_ADDR = 32767
-
-PREDEFINED_SYMBOLS = {
-    "SP": 0,
-    "LCL": 1,
-    "ARG": 2,
-    "THIS": 3,
-    "THAT": 4,
-    "R0": 0,
-    "R1": 1,
-    "R2": 2,
-    "R3": 3,
-    "R4": 4,
-    "R5": 5,
-    "R6": 6,
-    "R7": 7,
-    "R8": 8,
-    "R9": 9,
-    "R10": 10,
-    "R11": 11,
-    "R12": 12,
-    "R13": 13,
-    "R14": 14,
-    "R15": 15,
-    "SCREEN": 16384,
-    "KBD": 24576,
-}
-
-DEST = {
-    "": 0b000 << 3,
-    "M": 0b001 << 3,
-    "D": 0b010 << 3,
-    "MD": 0b011 << 3,
-    "A": 0b100 << 3,
-    "AM": 0b101 << 3,
-    "AD": 0b110 << 3,
-    "AMD": 0b111 << 3,
-}
-
-JMP = {
-    "": 0b000,
-    "JGT": 0b001,
-    "JEQ": 0b010,
-    "JGE": 0b011,
-    "JLT": 0b100,
-    "JNE": 0b101,
-    "JLE": 0b110,
-    "JMP": 0b111,
-}
-
-
-COMP = {
-    "0": 0b0101010 << 6,
-    "1": 0b0111111 << 6,
-    "-1": 0b0111010 << 6,
-    "D": 0b0001100 << 6,
-    "A": 0b0110000 << 6,
-    "M": 0b1110000 << 6,
-    "!D": 0b0001101 << 6,
-    "!A": 0b0110001 << 6,
-    "!M": 0b1110001 << 6,
-    "-D": 0b0001111 << 6,
-    "-A": 0b0110011 << 6,
-    "-M": 0b1110011 << 6,
-    "D+1": 0b0011111 << 6,
-    "A+1": 0b0110111 << 6,
-    "M+1": 0b1110111 << 6,
-    "D-1": 0b0001110 << 6,
-    "A-1": 0b0110010 << 6,
-    "M-1": 0b1110010 << 6,
-    "D+A": 0b0000010 << 6,
-    "A+D": 0b0000010 << 6,
-    "D+M": 0b1000010 << 6,
-    "M+D": 0b1000010 << 6,
-    "D-A": 0b0010011 << 6,
-    "D-M": 0b1010011 << 6,
-    "A-D": 0b0000111 << 6,
-    "M-D": 0b1000111 << 6,
-    "D&A": 0b0000000 << 6,
-    "A&D": 0b0000000 << 6,
-    "D&M": 0b1000000 << 6,
-    "M&D": 0b1000000 << 6,
-    "D|A": 0b0010101 << 6,
-    "A|D": 0b0010101 << 6,
-    "D|M": 0b1010101 << 6,
-    "M|D": 0b1010101 << 6,
-}
-
-
-def find_illegal_symbol_char(symbol):
-    for c in symbol:
-        if (not c.isascii()) or (not (c.isalnum() or c in "_.$:")):
-            return c
-
-    return None
-
-
-def print_symbols(symbols):
-    print("====== SYMBOLS =====")
-    print("label\taddr")
-    for label, addr in symbols.items():
-        print(f"{label}\t{addr}")
-
-
-def print_binary_and_asm(binary, asm_lines):
-    # binary and asm_lines are assumed to be of the same length
-    print("====== RESULTS =====")
-    print("addr\tbinary          \tinst")
-    for line_no, bin, asm in zip(range(len(binary)), binary, asm_lines):
-        print(f"{line_no}\t{bin:016b}\t{asm}")
-
-
-def write_binary(file, binary):
-    for inst in binary:
-        file.write(f"{inst:016b}\n")
-
-
-def assemble_inst(asm_line):
-    if asm_line.startswith("@"):
-        # A instruction
-        addr_str = asm_line[1:]
-        addr = int(addr_str)
-        if addr > MAX_ADDR:
-            print(f"Address out of range: {addr}", file=stderr)
-            exit(EXIT_CODES["addr_error"])
-
-        return addr
-    else:
-        # dest=comp;jmp
-        inst = 0xE000
-        dest, _, rhs = asm_line.partition("=")
-        if not rhs:
-            rhs = dest
-            dest = ""
-
-        comp, _, jmp = rhs.partition(";")
-        if dest not in DEST:
-            print(f"Invalid destination: {dest}", file=stderr)
-            exit(EXIT_CODES["syntax_error"])
-
-        inst |= DEST[dest]
-
-        if jmp not in JMP:
-            print(f"Invalid jump instruction: {jmp}", file=stderr)
-            exit(EXIT_CODES["syntax_error"])
-
-        inst |= JMP[jmp]
-
-        if comp not in COMP:
-            print(f"Invalid computation: {comp}", file=stderr)
-            exit(EXIT_CODES["syntax_error"])
-
-        inst |= COMP[comp]
-
-        return inst
-
-
-def assembler(input_fn, verbose):
-    try:
-        input_file = open(input_fn, "r")
-    except FileNotFoundError:
-        print(f"Cannot open input file: {input_fn}", file=stderr)
-        exit(EXIT_CODES["file_error"])
-
-    asm_lines = []
-    line = input_file.readline()
-    asm_line_cnt = 0
-    user_symbols = {}
-    while line:
-        line = line.rstrip("\n")
-        # throw away comment and whitespace
-        asm_line = line.partition("//")[0].replace(" ", "").replace("\t", "")
-        if not asm_line:
-            # skip blank or comment line
-            line = input_file.readline()
-            continue
-
-        if asm_line.startswith("(") and asm_line.endswith(")"):
-            # asm_line may be a label
-            label = asm_line[1:-1]
-            illegal_char = find_illegal_symbol_char(label)
-            if illegal_char is not None:
-                print(f"Illegal character: {illegal_char}", file=stderr)
-                exit(EXIT_CODES["illegal_char"])
-
-            if label in user_symbols or label in PREDEFINED_SYMBOLS:
-                print(f"Symbol {label} already exists", file=stderr)
-                exit(EXIT_CODES["symbol_error"])
-
-            user_symbols[label] = asm_line_cnt
-        else:
-            # asm_line may be an instruction
-            asm_lines.append(asm_line)
-            asm_line_cnt += 1
-            if asm_line_cnt > MAX_INST_LEN:
-                print(
-                    f"Max number of instruction ({MAX_INST_LEN}) exceeded", file=stderr
-                )
-                exit(EXIT_CODE_SIZE_EXCEEDED)
-
-        line = input_file.readline()
-
-    input_file.close()
-
-    # find and assign address to variables on the fly
-    addr = 16  # variable addresses start at 16
-    for line_no, asm_line in enumerate(asm_lines):
-        if not asm_line.startswith("@"):
-            continue
-
-        addr_str = asm_line[1:]  # whatever comes after the @
-        if not addr_str:
-            print("Address cannot be empty", file=stderr)
-            exit(EXIT_CODES["addr_error"])
-
-        if addr_str.isascii() and addr_str.isdecimal():
-            # address is decimal constant
-            continue
-
-        if addr_str in PREDEFINED_SYMBOLS:
-            asm_lines[line_no] = f"@{PREDEFINED_SYMBOLS[addr_str]}"
-        elif addr_str in user_symbols:
-            asm_lines[line_no] = f"@{user_symbols[addr_str]}"
-        else:
-            user_symbols[addr_str] = addr
-            asm_lines[line_no] = f"@{addr}"
-            addr += 1
-
-    binary = []
-    for asm_line in asm_lines:
-        binary.append(assemble_inst(asm_line))
-
-    if verbose:
-        print_symbols(user_symbols)
-        print_binary_and_asm(binary, asm_lines)
-
-    output_fn = (
-        input_fn[:-4] + ".hack" if input_fn.endswith(".asm") else input_fn + ".hack"
-    )
-    try:
-        output_file = open(output_fn, "w")
-    except:
-        print(f"Cannot open output file: {output_fn}", file=stderr)
-
-    write_binary(output_file, binary)
-    output_file.close()
-    print(f"Binary written to {output_fn}")
-
-
-if __name__ == "__main__":
-    parser = ArgumentParser()
-    parser.add_argument("-v", "--verbose", action="store_true", help="verbose mode")
-    parser.add_argument("input_fn", help="input file in assembly")
-    args = parser.parse_args()
-    assembler(args.input_fn, args.verbose)
diff --git a/projects/06/hack-as/test/compare.hack b/projects/06/hack-as/test/compare.hack
deleted file mode 100644
index f33a9d1..0000000
--- a/projects/06/hack-as/test/compare.hack
+++ /dev/null
@@ -1,25 +0,0 @@
-0000000000000000
-1111110000010000
-0000000000010111
-1110001100000110
-0000000000010000
-1110001100001000
-0100000000000000
-1110110000010000
-0000000000010001
-1110001100001000
-0000000000010001
-1111110000100000
-1110111010001000
-0000000000010001
-1111110000010000
-0000000000100000
-1110000010010000
-0000000000010001
-1110001100001000
-0000000000010000
-1111110010011000
-0000000000001010
-1110001100000001
-0000000000010111
-1110101010000111
diff --git a/projects/06/hack-as/test/conventional.asm b/projects/06/hack-as/test/conventional.asm
deleted file mode 100644
index 5510424..0000000
--- a/projects/06/hack-as/test/conventional.asm
+++ /dev/null
@@ -1,32 +0,0 @@
-// conventional asm a sane person would write

-// draw a rectangle on top left of screen

-// width 16px, height specified in RAM[0]

-@0

-D=M

-@INFINITE_LOOP

-D;JLE	// reject if height is negative

-@counter

-M=D

-@SCREEN

-D=A

-@address

-M=D

-(LOOP)

-	@address

-   	A=M

-   	M=-1

-   	@address

-   	D=M

-   	@32

-   	D=D+A

-   	@address

-   	M=D

-   	@counter

-   	MD=M-1

-   	@LOOP

-   	D;JGT

-

-(INFINITE_LOOP)

-	@INFINITE_LOOP

-	0;JMP

-

diff --git a/projects/06/hack-as/test/valid.asm b/projects/06/hack-as/test/valid.asm
deleted file mode 100644
index d705f1e..0000000
--- a/projects/06/hack-as/test/valid.asm
+++ /dev/null
@@ -1,29 +0,0 @@
-// valid asm, but with unnecessary whitespace, = and ;
-@ 0		// unnecessary space
-D=M
-@INFINITE_LOOP
-=D;JLE		// unnecessary =
-@counter
-M=D;		// unnecessary ;
-@SCREEN
-D = A		// unnecessary spaces
-@address
-M = D;		// unnecessary spaces and ;
-( LOOP )	// unnecessary spaces
-	@address
-   	A=M
-   	M=-1
-   	@address
-   	D=M
-   	@32
-   	D=D+A
-   	@address
-   	M=D
-   	@counter
-   	MD=M-1
-   	@LOOP
-   	D;JGT
-
-(INFINITE_LOOP)
-	@INFINITE_LOOP
-	0;JMP