Scheme 86: An Architecture for Microcoding a Scheme Interpreter

Abstract

I describe the design and implementation plans for a computer that is optimized as a microcoded interpreter for Scheme. The computer executes SCode, a typed-pointer representation. The memory system has low-latency as well as high throughput. Multiple execution units in the processor complete complex operations in less than one memory cycle, allowing efficient use of memory bandwidth. The processor provides hardware support for tagged data objects and runtime type checking. I will discuss the motivation for this machine, its architecture, why it can interpret Scheme efficiently, and the computer-aided design tools developed for building this computer.