# Alt key codes - 2 digits vs 3 digits

Open up notepad and type Alt+Numpad 1+ Numpad 6 and this give a character ► But when I type Alt+Numpad 0+ Numpad 1+ Numpad 6 I dont get any character

Whats the difference here

When I type Alt+2+2+5 I get ß When I type Alt+225225 I get ╔ which corresponding to Alt+201

How is Alt+225225 is same as Alt+201?

Thanks

-

## migrated from stackoverflow.comOct 2 '09 at 17:09

This question came from our site for professional and enthusiast programmers.

I avoid the question of different numbers of digits returning different by always entering 4 digits. Alt + Numpad0 + Numpad0 + Numpad1 + Numpad6. – JMD Oct 2 '09 at 17:21

The reason that Alt+Num16 gives you ►, while Alt+Num016 gives you nothing, is so you can access both the characters that are mapped to codes 1 through 31 by IBM PC code page 437 and the control characters in that range of ASCII. You enter a leading zero for the control characters and omit leading zeros for the graphic characters in this set: ☺☻♥♦♣♠•◘○◙♂♀♪♫☼►◄↕‼¶§▬↨↑↓→←∟↔▲▼

To give this a try, you can type Alt+Num9 for ○ (circle) or Alt+Num09 for Tab and Alt+Num13 for ♪ or Alt+Num013 for Return. Let's just say that the use for ASCII 16 (Ctrl-P) is lost in the mists of time.

If you are using a Unicode-compatible application such as Wordpad, entering Alt+Num225225 is the same as Alt+Num28617 (225225 % 65536 = 28617) which is character U+6FC9 or 濉

-

225225 % 256 = 201

Or, the binary representation of 225225 ends in the binary representation of 201.

-