(2.4.1) Cray 1

  1. Richard M. Russell. The Cray-1 Computer System, Communications of the ACM, January 1978, pp. 63-72. ACM DL Link


1978

Vector processing engine
     128 MFLOPS! cool. 
     Cylinder to ensure wiring distances small

Banked memory

Registers
     A > Address(24 bit), B > cache for A
     S > Data (64 bit), T > cache for S
     V > Vector, VM > vector mass
     Supporting : VL > Vector Length, VM, PC, Base Address, Limit Address, Flag, Mode, and exchange Addr

Chaining
     result of one func unit as input to other 
     > bypass basically
Interrupt 
     stop PC inc, complete mem operations, vector proc
     call exchanges by OS to handler

Software/Vector processing
     Cray OS, Fortran compiler
     2 or 4 or more elements in vectors > better than scalar (earlier 100s required)
     complex vector routines > scalar loop calls
     array increments = integer, start point and array. 

Front End 
     at least a minicomputer connected by a 
     cray link

Cooling problems
Circuit boards
     make wires equal length, or standing waves on ground line. prop delay balancing > purely resistive load. 
     5 layer PCB