
 Binarycoded decimal  Wikipedia, the free encyclopedia 
  Binarycoded decimal (BCD) is, after character encodings, the most common way of encoding decimal digits in computing and in electronic systems. 
  In the Decimal Architecture IBM 7070, IBM 7072, and IBM 7074 alphamerics were encoded using digit pairs (using twooutoffive code in the digits, not BCD) of the 10digit word, with the "zone" in the left digit and the "digit" in the right digit. 
  In BCD, a digit is usually represented by four (binary) bits, of which the leftmost (written conventionally) has value 8, and the remaining three have values 4, 2, and 1. 
 en.wikipedia.org /wiki/Binarycoded_decimal (1233 words) 
