This short section of the MPS10 document first asks when one should choose a microprocessor over hardwired logic.
http://www.willegal.net/blog/wp-content/uploads/2019/11/MPS10-why-perf-PDP.pdf
There is a paragraph discussing how to evaluate micro-processors, which is basically the same as evaluating any computer. The next section asks why use the Intel chip – the answer being that it’s about the only one available. Perhaps at the time that it was written, the IMP-16 wasn’t known about or available or the IMP-16 was dismissed for other reasons.
The next section starts discussing the MPS10. One thing that is called out, is that the MPS10 is a member of DECs M series module line. I don’t know anything about the M series modules, but perhaps some existing M series modules would be able to interoperate with the MPS10.
The next section lists the five modules that make up the MPS processor system. These modules are:
The M7341 processor module
The M7342 monitor/control module
Three size variations of the M7344 Memory module (1K, 2K, 4K)
The M7345 4K Prom memory module
The m7346 external event detection module
The last part of this section discusses the relationship of the MPS10 with other Digital Equipment Corporation Computers. The first statement of this section states that the MPS10 is not a minicomputer and is not intended to compete with minicomputers. It was designed to be a dedicated controller, a replacement for fixed logic designs.
“It should be considered to be an extremely useful augmentation of and addition to, DEC’s existing arsenal of processing devices.”
One thing to keep in mind, is that DEC had a very successful line of minicomputers, and undercutting that business from within the company, would have been a very risky proposition. Any change of architecture away from the PDP series would leave a potential customer, the option of evaluating systems from competing businesses as well as any new DEC architecture. The developers of the MPS10 had to be careful to not threaten the existing DEC business, which could account for some of the language in this document.