The Air Force plans to use a standard instruction set architecture, designated 1750A, for all of its embedded computers. This paper describes the potential usefulness of the 1750A standard for spacecraft avionics, the characteristics of the various processors that conform to 1750A, and the hardware design issues for the computers that will employ 1750A in an aerospace environment. What the instructions are in the 1750A standard and why the standard is better than other instruction sets for use in embedded computers are not discussed.

The paper claims that this standard will dominate avionics and save the Air Force money. The argument for the standard dominating Air Force avionics is strong. But it would be more convincing if some of the examples were from aircraft avionics rather than spacecraft. That the 1750A standard will save the Air Force money is less convincing. Using a common instruction set does not guarantee “transportability of operational modules.” The system software--operating system, assembler, loader, etc.--has to be designed with transportability in mind. Instruction set commonality only gives an opportunity for transportability and associated cost savings.

These final concerns may be more political than technical. Ada is mandated by the Department of Defense to be the programming language for embedded computers. One would imagine that for the 1750A to be an instruction set of the future it would have a close relationship to Ada. Does it? This paper does not say. Why is this just an Air Force standard? What happened to the Army, Navy, and the rest of the Department of Defense?