Standard sign values are 1100 (hex C) for positive (+) and 1101 (D) for negative (?). This convention was derived from abbreviations for accounting terms (Credit and Debit), as packed decimal coding was widely used in accounting systems.

But there are other encoding schemes.

BCD is a concept, not a specific encoding.

http://en.wikipedia.org/wiki/Binary-code...

Hey, I need help on how to write negative binary number using BCD (Binary Coded Decimal) technique.

Is it possible to write a negative binary using BCD?

Furthermore, can we do binary subtraction with BCD?

Thanks in advance.