diff --git a/src/compiler/compiler.c b/src/compiler/compiler.c
index f636241..c4130f9 100644
--- a/src/compiler/compiler.c
+++ b/src/compiler/compiler.c
@@ -162,7 +162,8 @@ static void readLabel(Compiler* cmp){
             return;
         }
 
-        if(!isAlphabeticalLower(c) && !isAlphabeticalUpper(c) && !isDigit(c)){
+        if(!isAlphabeticalLower(c) && !isAlphabeticalUpper(c) && !isDigit(c) &&
+            c != '_' && c != '.'){
             setError(Error_unexpectedCharacter(c));
             return;
         }
@@ -251,6 +252,83 @@ static void readInstruction(Compiler* cmp){
     List_Token_push(&cmp->tokens, tok);
 }
 
+static void readChar(Compiler* cmp){
+    Token tok = Token_construct(TokenType_Char, cmp->pos, 0);
+    cmp->pos++;
+    cmp->column++;
+    
+    while(cmp->pos < cmp->code_len){
+        char c = cmp->code[cmp->pos];
+        // end of line
+        if(c == '\r' || c == '\n'){
+            setError(Error_unexpectedCharacter(cmp->code[--cmp->pos]));
+            return;
+        }
+
+        if(c == '\''){
+            tok.length = cmp->pos - tok.begin + 1;
+            List_Token_push(&cmp->tokens, tok);
+            return;
+        }
+
+        cmp->column++;
+        cmp->pos++;
+    }
+    
+    // end of file
+    setError(Error_endOfFile);
+}
+
+static void readString(Compiler* cmp){
+    Token tok = Token_construct(TokenType_String, cmp->pos, 0);
+    cmp->pos++;
+    cmp->column++;
+    
+    while(cmp->pos < cmp->code_len){
+        char c = cmp->code[cmp->pos];
+        // end of line
+        if(c == '\r' || c == '\n'){
+            setError(Error_unexpectedCharacter(cmp->code[--cmp->pos]));
+            return;
+        }
+
+        if(c == '"'){
+            tok.length = cmp->pos - tok.begin + 1;
+            List_Token_push(&cmp->tokens, tok);
+            return;
+        }
+
+        cmp->column++;
+        cmp->pos++;
+    }
+    
+    // end of file
+    setError(Error_endOfFile);
+}
+
+static void readNumber(Compiler* cmp){
+    Token tok = Token_construct(TokenType_Number, cmp->pos, 0);
+    cmp->pos++;
+    cmp->column++;
+    
+    while(cmp->pos < cmp->code_len){
+        char c = cmp->code[cmp->pos];
+
+        if(c == '\r' || c == '\n' || c == ' ' || c == '\t' || c == ',' || c == ';'){
+            tok.length = cmp->pos - tok.begin;
+            List_Token_push(&cmp->tokens, tok);
+            return;
+        }
+
+        cmp->column++;
+        cmp->pos++;
+    }
+    
+    // end of file
+    tok.length = cmp->pos - tok.begin;
+    List_Token_push(&cmp->tokens, tok);
+}
+
 static bool lex(Compiler* cmp){
     returnErrorIf_auto(cmp->state != CompilerState_Initial);
     cmp->state = CompilerState_Lexing;
@@ -270,13 +348,20 @@ static bool lex(Compiler* cmp){
             case '.':
                 readLabel(cmp);
                 break;
+            case '"':
+                readString(cmp);
+                break;
+            case '\'':
+                readChar(cmp);
+                break;
             default:
                 // try read instruction
-                if(isAlphabeticalLower(c) || isAlphabeticalUpper(c)){
+                if(isAlphabeticalLower(c) || isAlphabeticalUpper(c))
                     readInstruction(cmp);
-                    break;
-                }
+                else if(isDigit(c))
+                    readNumber(cmp);
                 else returnError(Error_unexpectedCharacter(c));
+                break;
         }
 
         if(cmp->state == CompilerState_Error)
@@ -358,7 +443,7 @@ bool Compiler_compileTasm(Compiler* cmp, cstr source_file_name, cstr out_file_na
             char* tokstr = malloc(4096);
             strncpy(tokstr, cmp->code + t.begin, t.length);
             tokstr[t.length] = 0;
-            printf("[l:%2u, c:%2u] %s '%s'\n", 
+            printf("[l:%3u, c:%3u] %s '%s'\n", 
                 pos.line, pos.column,
                 TokenType_toString(t.type), tokstr);
             free(tokstr);
diff --git a/src/compiler/token.c b/src/compiler/token.c
index bc4f836..29ffecd 100644
--- a/src/compiler/token.c
+++ b/src/compiler/token.c
@@ -1,15 +1,19 @@
 #include "token.h"
 
-static cstr TokenType_str[] = {
+static cstr _TokenType_str[] = {
     "Unset",
     "SingleLineComment",
     "MultiLineComment",
     "Label",
     "Instruction",
     "Argument",
-    "Data",
+    "Number",
+    "Char",
+    "String",
 };
 
 cstr TokenType_toString(TokenType t){
-    return TokenType_str[t];
+    if(t >= sizeof(_TokenType_str) / sizeof(cstr))
+        return "!!INDEX_ERROR!!";
+    return _TokenType_str[t];
 }
diff --git a/src/compiler/token.h b/src/compiler/token.h
index 7ee5dde..8e3d744 100644
--- a/src/compiler/token.h
+++ b/src/compiler/token.h
@@ -8,16 +8,17 @@ typedef enum TokenType {
     TokenType_Label,
     TokenType_Instruction,
     TokenType_Argument,
-    TokenType_Data,
-    /* there is a place for 2 values left (TokenType must occupy 4 bits) */
+    TokenType_Number,
+    TokenType_Char,
+    TokenType_String,
 } TokenType;
 
 cstr TokenType_toString(TokenType t);
 
 typedef struct Token {
     u32 begin;          // some index in Compiler->code
-    u32 length : 28;    // length in characters (28 bits)
-    TokenType type : 4; // type of token (4 bits)
+    u32 length : 24;    // length in characters (24 bits)
+    TokenType type : 8; // type of token (8 bits)
 } Token;
 
 #define Token_construct(TYPE, BEGIN, END) ((Token){ .type = TYPE, .begin = BEGIN, .length = END })