#### What type of number “3 D“ is? Why? What do you mean by BCD and EBCDIC?

Subject Introduction to Computer System Set: 3.(d) Marks: 4 Year: 2009

3D is a Hexa-decimal number.

# Binary Coded Decimal

Binary Coded Decimal or BCD as it is more commonly called, is another process for converting decimal numbers into their binary equivalents.

As we naturally live in a decimal (base-10) world we need some way of converting these decimal numbers into a binary (base-2) environment that computers and digital electronic devices understand, and binary coded decimal code allows us to do that.

We have seen previously that an n-bit binary code is a group of “n” bits that assume up to 2n distinct combinations of 1’s and 0’s. The advantage of the Binary Coded Decimal system is that each decimal digit is represented by a group of 4 binary digits or bits in much the same way as Hexadecimal. So for the 10 decimal digits (0-to-9) we need a 4-bit binary code.

# EBCDIC (Extended Binary Coded Decimal Interchange Code) 