The machines in the series
There Honeywell Series 16 machines spanned the life of the minicomputer. The DDP-116 was the very first 16-bit minicomputer, and the H716 was introduced just as integrated microcomputers replaced minicomputers.
Why are they so little known?
Series 16 computers were used in a wide range of applications. However, they seem to be largely forgotten. They are certainly not nearly as well known as that DEC (Digital Equipment Corporation) machines such as the PDP8 and PDP11 family. Yet if you visit the Computer History Museum you will find that they have an example of each of the major machines in the series:
- The first ever 16-bit minicomputer.
- In the from of an IMP (Interface Message Processor). Arguably the first ever Internet router.
- In a very "Star Trek" style console as the "Kitchen Computer".
So it is clear that the world's best computer museum sees these as significant and influential machines. Why then are they not better known? Part of this must be because a relatively small number of these machines were ever made. But I also believe that part of the answer lies in the rather utilitarian applications that many of these machines were used in.
The DEC PDP machines were widely used in academic and scientific computing and had an influence that can still be seen in today's desktop microprocessor based systems. In contrast many of the Honeywell machines were used in control applications. In many ways they are the intellectual ancestors of todays micro-controllers.
The architect's view
Ed Thelen's Antique (lonesome) Computers site includes a series of The Computer Museum Reports. Volume 15 from Spring 1986 (cached) includes an article by Gardner Hendrie who designed the original DDP-116. In this article Gardner talks about CCC, and their technology that made the Series 16 machines viable, and the market-place pressures that lead to the decision to build a 16-bit machine.
The article also mentions that about 200 DDP-116 machines were built, and about 2000 DDP-516s. I've never seen an estimate of the number of machines elsewhere.