WinXP SP2 у меня русский профешонал.
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раздел Constants (а поиск втыкаешь)
The µVision3 accepts decimal constants, HEX constants, octal constants, binary constants, floating-point constants, character constants, and string constants.
Binary, Decimal, HEX, and Octal Constants
By default, numeric constants are decimal or base ten numbers. When you enter 10, this is the number ten and not the HEX value 10h. The following table shows the prefixes and suffixes that are required to enter constants in base 2 (binary), base 8 (octal), base 10 (decimal), and base 16 (HEX).
Base Prefix Suffix Example
Binary: None Y or y 11111111Y
Decimal: None T or none 1234T or 1234
Hexadecimal: 0x or 0X H or h 1234H or 0x1234
Octal: None Q, q, O, or o 777q or 777Q or 777o
Following are a few points to note about numeric constants.
Numbers may be grouped with the dollar sign character (“$”) to make them easier to read. For example, 1111$1111y is the same as 11111111y.
HEX constants must begin prefixed with a leading zero when the first digit in the constant is A-F.
By default, numeric constants are 16-bit values. They may be followed with an L to make them long, 32-bit values. For example: 0x1234L, 1234L, 1255HL.
When a number is entered that is larger than the range of a 16-bit integer , the number is promoted automatically to a 32-bit integer.
Вот линк
http://www.keil.com/support/man/docs/uv3/u...p_constants.htmЦитата(VAI @ Jul 20 2007, 15:09)

А в С нету двоичных чисел....
Ну мыж не Си используем а компилятор !
Сделали это авторы CVAVR HT-PICC CCS ввод двоичных чисел
и он работает ни как не связанно с Си.
Просто ЕСТЬ и все.
И в ХЕЛПЕ КЕЙЛА есть

а он ругается ...