diff --git a/main.py b/main.py
index 065565f..169a633 100644
--- a/main.py
+++ b/main.py
@@ -58,7 +58,13 @@ class Reader:
 		token_start = 0
 		token_line = 1
 		token_column = 0
-		for char in source:
+		source_len = len(source)
+		while index < source_len:
+			char = source[index]
+			if char == "#":
+				while index < source_len and source[index] != "\n":
+					index += 1
+				continue
 			if char.isspace():
 				if lexeme:
 					yield Token(
diff --git a/stdlib.sl b/stdlib.sl
index 045f3a6..0415b26 100644
--- a/stdlib.sl
+++ b/stdlib.sl
@@ -109,6 +109,50 @@ puts_finish_digits:
 }
 ;
 
+:asm @ {
+	mov rax, [r12]
+	mov rax, [rax]
+	mov [r12], rax
+}
+;
+
+:asm ! {
+	mov rax, [r12]
+	add r12, 8
+	mov rbx, [r12]
+	mov [rax], rbx
+	add r12, 8
+}
+;
+
+:asm mmap {
+	mov r9, [r12]
+	add r12, 8
+	mov r8, [r12]
+	add r12, 8
+	mov r10, [r12]
+	add r12, 8
+	mov rdx, [r12]
+	add r12, 8
+	mov rsi, [r12]
+	add r12, 8
+	mov rdi, [r12]
+	mov rax, 9
+	syscall
+	mov [r12], rax
+}
+;
+
+:asm munmap {
+	mov rsi, [r12]
+	add r12, 8
+	mov rdi, [r12]
+	mov rax, 11
+	syscall
+	mov [r12], rax
+}
+;
+
 :asm exit {
 	mov rdi, [r12]
 	add r12, 8
diff --git a/test.sl b/test.sl
index 29163b8..e6e258c 100644
--- a/test.sl
+++ b/test.sl
@@ -1,5 +1,12 @@
 import stdlib.sl
 
+:asm mem-slot {
+    lea rax, [rel print_buf]
+    sub r12, 8
+    mov [r12], rax
+}
+;
+
 : test-add
     5 7 + puts
 ;
@@ -32,6 +39,28 @@ import stdlib.sl
     2 5 swap - puts
 ;
 
+: test-store
+    mem-slot dup
+    123 swap !
+    @ puts
+;
+
+
+: test-mmap
+    0      # addr hint (NULL)
+    4096   # length (page)
+    3      # prot (PROT_READ | PROT_WRITE)
+    34     # flags (MAP_PRIVATE | MAP_ANON)
+    -1     # fd (ignored for MAP_ANON)
+    0      # offset
+    mmap
+    dup
+    1337 swap !
+    dup
+    @ puts
+    4096 munmap drop
+;
+
 : main
     test-add
     test-sub
@@ -41,5 +70,7 @@ import stdlib.sl
     test-drop
     test-dup
     test-swap
+    test-store
+    test-mmap
     0
 ;