VAX

an [|instruction set] architecture, developed by Digital Equipment Corporation (DEC) in the mid-1970s, to extend the PDP-11 architecture to a 32-bit [|orthogonal instruction set] while adding a complete virtual memory system to the simple paging and memory protection of the PDP-11. The first computer to use a VAX CPU was the [|VAX-11/780], which DEC referred to as a [|Superminicomputer]. DEC's VAX strategy was formulated by [|Gordon Bell]. || toc =Registers= VAX has 16 32-bit [|registers], R0-R15. R0-R11 general purpose, R12/AP the argument pointer, R13/FP the frame pointer, R14/SP the stack pointer, and R15/PC the program counter or instruction pointer.
 * Home * Hardware * VAX**
 * [[image:176px-DEC-VAX-8350-front-0a.jpg link="http://en.wikipedia.org/wiki/File:DEC-VAX-8350-front-0a.jpg"]] ||~ || **VAX**, (Virtual Address Extension)
 * VAX 8350 ||~ ||^ ||

=Instructions= The general form of a VAX instruction ... code opcode [ operand ] [ operand ] ... code ... has each component being one byte, the opcode a value in the range 0 - 255, and each operand consisting of two nibbles, the upper 4 bits specifying an addressing mode, and the lower 4 bits (usually) a register number (R0 - R15).  =MicroVAX= The **MicroVAX** was a family of low-end minicomputers implemented the VAX instruction set architecture, first introduced in 1984.

=Chess Programs=
 * Dappet
 * Matchess
 * Pion
 * Prodigy
 * Shess
 * Vaxchess

=See also=
 * DEC Alpha
 * PDP-11
 * Virtual Memory

=External Links=
 * [|VAX from Wikipedia]
 * [|List of VAX computers from Wikipedia]
 * [|NVAX from Wikipedia]
 * [|VAX-11 from Wikipedia]
 * [|VAX 8000 from Wikipedia]
 * [|VAX 7000/10000 from Wikipedia]
 * [|VAXstation from Wikipedia]
 * [|MicroVAX from Wikipedia]
 * [|MicroVAX 78032 from Wikipedia]
 * [|VAX Macro from Wikipedia]
 * [|OpenVMS from Wikipedia]
 * [|/resources/text/DEC/vax/] from The Computer History Museum

=References= =What links here?= include component="backlinks" page="VAX" limit="60"
 * Up one Level**