The system/360 and its mainframe successors are largely binary machines. In particular, addressing is entirely binary. They can, however, do both decimal and hexadecimal arithmetic in some situations too.
All this can be reduced to boolean algebra and, finally, to assorted configurations of NORs or NANDs: binary arithmetic can indeed be made to disappear, replaced by boolean algebra. These reductions are theoretically important; but, as I have had occasion to point out here before, you can cut yourself with Ockham's razor. In most cases it is appropriate, qua programmer although not perhaps qua circuit designer, to think of the z/Architecture HFP instructions as doing hexadecimal arithmetic and of the decimal and DFP instructions as doing decimal arithmetic John Gilmore, Ashland, MA 01721 - USA ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
