Keeping old computers alive for deeper understanding of computer architecture

Computer architectures, as they are seen by students, are getting more and more monolithic: few years ago a student had access to x86 processor on his or her laptop, SPARC server in the backyard, MIPS and PowerPC on large SMP system, and Alpha on calculation server. Today, only architectures that students experience writing program on are x86_64 and possibly ARM. On one hand, this simplifies their learning, but on the other hand, this makes it harder to discover options that are available in designing an instruction set architecture.

In this paper, we introduce our undergraduate course that teaches computer architecture design and evaluation that uses historic computers to make more processor architectures accessible to students. The collection of more than 270 old computers that were marketed in 1979 to 2014 are used in the class. These computers had to be repaired and restored to working condition before using in exercise for the undergraduate students. By experiencing different architectures from what is used everyday, students learn the context of features that are standard today.

This paper also shows power consumption and benchmark comparison results obtained using old computers outside classroom. These data are also used as the basis for learning about concepts and issues of computer architecture.