@@ -3,6 +3,8 @@ *.cmp
 *.tst
 *.out
 
-# ignore machine code files in project 05
+# ignore prokect 05 machine code files, project 06 test files, build artifacts
 projects/05/*.hack
+projects/06/bin/*
+projects/06/test/*
 

@@ -0,0 +1,18 @@ 
+
+CFLAGS = -std=c99 -Wall -Wextra
+
+all: bin/assembler1
+#all: bin/assembler1 bin/bin2text
+
+# TODO: clean up, make more Makefile-idiomatic
+
+bin/assembler1: assembler1/assembler1.c
+	$(CC) $(CFLAGS) -o $@ $<
+
+#bin/bin2text: bin2text.c
+#	$(CC) $(CFLAGS) -o $@ $<
+
+clean:
+	rm -vf bin/*
+
+.PHONY: clean

@@ -0,0 +1,148 @@ 
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "../bindump.h"
+
+#define DEBUG(x) printf(x)
+
+void die(const char *err_msg, int exit_val)
+{
+	perror(err_msg);
+	exit(exit_val);
+}
+
+void alert(const char *err_msg)
+{
+	fprintf(stderr, "%s", err_msg);
+}
+
+/*
+uint16_t parse_a_type(const char *line)
+{
+	// eventually, if error, die("error: TODO explain...\n", -1);
+	DEBUG("parse_a_type()\n");
+	return 0x0000; // STUB, A-type MSB == 0 anyway
+}
+
+uint16_t parse_c_type(const char *line)
+{
+	DEBUG("parse_c_type()\n");
+	return 0x8000; // STUB, C-type MSB == 1 anyway
+}
+
+// does not care about line line length; exits at first newline or after
+// relevant portion parsed (allows for syntactically-incorrect lines, I know)
+uint16_t parse_instruction_w_type(const char *line, uint16_t *instruction)
+{
+	char c;
+	size_t i = 0;
+
+	while ((c = line[i]) != '\n') {
+		if (c == ' ' || c == '\t')
+			;  // skip whitespace
+		else if (c == '@') {
+			instruction = parse_a_type(line);
+			break;
+		} else if (c >= '!' && c < '~') {
+			instruction = parse_c_type(line);
+			break;
+		} else {
+			die("error: TODO explain...\n", -1);
+		}
+
+		++i;
+	}
+
+	ld.line_parsed = true;
+	return ld;
+}
+*/
+
+bool parse_next_instruction(const char *line, uint16_t *instruction)
+{
+	*instruction = 1337; // STUB, should be 0x539, 0b0000010100111001
+
+	return true;
+}
+
+/* return false for comment or invalid assembly instruction */
+bool parse_line(const char *line, size_t line_len, uint16_t *instruction)
+{
+	char c;
+	bool slash_found = false;
+	size_t i;
+
+	if (line_len == 0 || line_len == 1)
+		return false;
+
+	// filter out comment lines
+	//for (i = 0; (c = line[i]) != NULL; ++i) {
+	for (i = 0; i < line_len; ++i) {
+		c = line[i];
+
+		if (c == ' ' || c == '\t') {
+			continue;
+		} else if (c == '/') {
+			if (slash_found) {
+				// second slash means this is a comment
+				return false;
+			}
+			slash_found= true;
+			continue;
+		} else if (slash_found) {
+			// this char not slash, but previous was: invalid syntax
+			// TODO: add line, column numbers
+			alert("\tsyntax error: found '/', comments "
+			      "need '//'\n");
+			return false;
+		} else {
+			// non-whitespace/slash char discovered
+			break;
+		}
+	}
+
+	// comment not found, so attempting to parse instruction
+	return parse_next_instruction(line, instruction);
+}
+
+const char *test_lines[8] = {"// this is a comment\n",
+                             "@12345\n",
+                             "\n",
+                             "M+1\n",
+                             "@98\n",
+                             "// this is another comment\n",
+                             "/ this is a broken comment\n",
+                             "D=M;JNE\n"};
+size_t test_lines_len = 8;  // TODO calculate
+
+int main()
+{
+	// TODO: read file by lines, parse instructions
+	bool result = false; 
+	uint16_t instruction;
+	size_t test_line_len;
+
+	// New organization allows code to eventually work with lines fetched
+	// from a 'fgets()' loop or something
+
+	// for testing
+	for (size_t i = 0; i < test_lines_len; ++i) {
+		printf("testing %lu: line to assemble: %s", i, test_lines[i]);
+		test_line_len = strlen(test_lines[i]);
+		result = parse_line(test_lines[i], test_line_len, &instruction);
+		if (result) {
+			printf("instruction: 0x%x  |  ", instruction);
+			bindump_word16(instruction); // output instruction as binary
+			putchar('\n');
+		}
+		/* else {
+			printf("\tcomment or invalid syntax encountered\n");
+		}*/
+	}
+
+	return 0;
+}
+

@@ -1,30 +0,0 @@ 
-#include <stdio.h>
-#include <stdint.h>
-
-void output_binary(uint8_t b)
-{
-	char i, msb;
-
-	for (i = 0; i < 8; ++i) {
-		msb = b & 0x80;
-		if (msb)
-			putchar('1');
-		else
-			putchar('0');
-		b <<= 1;
-	}
-}
-
-int main(int argc, char *argv[])
-{
-	char c, next_line = 0;
-
-	while ((c = getchar()) != EOF) {
-		output_binary(c);
-		++next_line;
-		if (next_line % 2 == 0)
-			putchar('\n');
-	}
-
-	return 0;
-}

@@ -0,0 +1,21 @@ 
+#include <stdio.h>
+#include <stdint.h>
+
+void bindump_word16(uint16_t w)
+{
+	unsigned char i, msb;
+	char binary_string[17];
+	binary_string[16] = '\0';
+
+	for (i = 0; i < 16; ++i) {
+		msb = (char)(w >> 15);
+
+		if (msb != 0)
+			binary_string[i] = '1';
+		else
+			binary_string[i] = '0';
+		w <<= 1;
+	}
+	printf("%s", binary_string);
+}
+