RTX2010

The RTX2010, manufactured by Intersil, is a radiation hardened stack machine microprocessor which has been used in numerous spacecraft.

Characteristics
It is a two-stack machine, each stack 256 words deep, that supports direct execution of Forth. Subroutine calls and returns only take one processor cycle and it also has a very low and consistent interrupt latency of only four processor cycles, which lends it well to realtime applications.

History
In 1983, Chuck Moore implemented a processor for his programming language Forth as a gate array. As Forth can be considered a dual stack virtual machine, he made the processor, Novix N4000 (later renamed NC4016), as a dual-stack machine. In 1988, an improved processor was sold to Harris Semiconductor, who marketed it for space applications as the RTX2000.

Example spacecraft that use the RTX2010

 * Advanced Composition Explorer (ACE)
 * NEAR/Shoemaker
 * TIMED
 * Rosetta's lander - Philae