Some machines have special hardware instructions and native data types specifically designed for dealing with decimal data (of which monetary data is the most common example). IBM's venerable 360/370/390 series of mainframes has an entire instruction set devoted to handling decimal data. A special variable-length data type known as "packed decimal" encodes a decimal value as a series of 4-bit decimal digits (0-9) with each byte containing two digits. Cobol, widely used for data-processing applications on IBM mainframes, makes extensive use of the packed decimal data format and the decimal instruction set to process monetary data.
—J.N.A.
Back to Article