Simple-As-Possible

The Simple-As-Possible (SAP) computer is a simplified computer architecture designed for educational purposes in the book "Digital Computer Electronics" (DEC) by Albert Paul Malvino and Jerald A. Brown. Fully Turing-complete, the SAP architecture serves as an example in DEC of building and analyzing complex logical systems with digital electronics. DEC describes three versions of this computer: SAP-1, SAP-2, and SAP-3, each building upon the previous.
Variants.
Ben Eater's Design.
YouTuber and former Khan Academy employee Ben Eater created a tutorial building an 8-bit Turing-complete SAP computer on breadboards from logical chips (7400-series) capable of running simple programs such as computing the Fibonacci sequence. Eater's design consists of the following modules:
Ben Eater's design has inspired multiple other variants and improvements, primarily on Eater's Reddit forum. Some examples of improvements are: