40	 Fingers or Fists The Choice of Decimal or Binary Representation	 The binary number system offers many advantages over a decimal representation for a high-performance general-purpose computer. The greater simplicity of a binary arithmetic unit and the greater compactness of binary numbers both contribute directly to arithmetic speed. Less obvious and perhaps more important is the way binary addressing and instruction formats can increase the overall performance. Binary addresses are also essential to certain powerful operations which are not practical with decimal instruction formats. On the other hand decimal numbers are essential for communicating between man and the computer. In applications requiring the processing of a large volume of inherently decimal input and output data the time for decimal-binary conversion needed by a purely binary computer may be significant. A slower decimal adder may take less time than a fast binary adder doing an addition and two conversions. A careful review of the significance of decimal and binary addressing and both binary and decimal data arithmetic supplemented by efficient conversion instructions.
