160Chapter 2 Instruction Set Principles and ExamplesThe many appendices may satisfy readers interested in instruction set archi-tecture: Appendix B compares seven popular load-store computers with MIPS.Appendix C describes the most widely used instruction set, the Intel 80x86, andcompares instruction counts for it with that of MIPS for several programs. Forthose interested in the historical computers, Appendix D summarizes the VAX ar-chitecture and Appendix E summarizes the IBM 360/370.One’s eyebrows should rise whenever a future architecture is developed with a stack- or register-oriented instruction set. [p. 20]Meyers The earliest computers, including the UNIVAC I, the EDSAC, and the IAS com-puters, were accumulator-based computers. The simplicity of this type of computermade it the natural choice when hardware resources were very constrained. Thefirst general-purpose register computer was the Pegasus, built by Ferranti, Ltd. in1956. The Pegasus had eight general-purpose registers, with R0 always being zero.