Transpute

A transputer is a family of microprocessors from the 1980s, developed by Inmos to make parallel computing practical by treating each chip as a self-contained processing node with its own RAM, scheduler, and high-speed serial links. Conceived by David May and Robert Milne, transputers were intended as building blocks that could be wired into scalable multiprocessing networks, with spare cycles on any node usable for other tasks. For a time they were widely viewed as a promising path for future computers; although they never replaced conventional CPUs, their concepts - processor-in-memory integration, built-in communication links and lightweight process scheduling - influenced later architectures and early system-on-chip thinking.

Technically, transputers used a microcoded datapath designed for many single-cycle instructions, dynamic logic for compact speed, and an internal clock derived from a slower external clock (5 MHz external, 20 MHz internal with four non-overlapping phases). Each chip offered up to four "os-link" serial ports running 5/10/20 Mbit/s for point-to-point message passing; larger networks required relaying across hops (mitigated by an Inmos zero-delay switch). Chips could boot from local ROM or be loaded over links using a BootFromROM pin, and hardware support scheduled link traffic and interprocess communication. Variants ranged from 16- to 32-bit and floating-point models, and later cores fed into reusable microcore and SoC developments.