The HP 2100S minicomputer was designed in the early 1970s using small-scale integration logic chips and core memory. It has a 16-bit word length and a 16-bit address space. My machine has 32k bytes of core memory, arranged in four 8k planes. That's a fully-expanded memory system for the 2100.

The machine has a front panel with lights and switches for access to memory and register contents. An HP 2748B paper tape reader can also be connected for program loading.

• HP 2100 Archives. The place to go for 2100 manuals and software.
• The Computer History Museum have an HP 2100 in the Visible Storage area.
• University of Stuttgart Computer Museum. Includes a photo of a 2100 with a full set of I/O interface cards. Text in German.
• Bob Supnik's Simulator includes a setup that will simulate an HP 2100. Now you can run 2100 programs on more modern hardware!
• Some photos from the HP manuals, showing complete systems in racks.