The Series 16 computers were originally designed by Computer Control Company, which was then bought by Honeywell in 1966.
Series 16 computers were used in a wide range of applications. Many were used in computer control applications, and many educational establishments used them as general purpose computers.
The most prominent application of them relates to the origins of the internet. The DDP-516 was used as the basis of "Interface Message Processors" or IMPs that were used to connect the very first networked computers to the ARPANET.
The DDP-516, introduced in 1966, and the later H316, which has an identical instruction set, form the core of the Series-16. The DDP-116 is clearly the forerunner of these machines, but seems to have had a limited impact commercially. The DDP-416 appears to be a development that is off the main path for the Series 16. The H716 seems to have come too late to be commercially successful.
Thanks to Adrian Wise for this information.
About this computer, Mr. Richard Pearson said us:
The picture is copied from the programming manual of the second computer that I was associated with, in 1966. The Honeywell DDP-516 was chosen for its high clock speed (aprox. 1.1 MHz) and expandability to 32 K of 16 bit words. Card and paper tape readers were the initial inputs with mag tape drives added as the system development progressed. The final configuration included a hard disc drive the size of a large upright freezer. Assorted special purpose devices were controlled by this state of the art unit. This system was done for NSA by a civilian R&D firm.