Hewlett-Packard 2114B  
Written by Accutron on 2006-10-10  

The Hewlett-Packard 2114B computer is a size-reduced, cost-reduced descendant of the original HP 2116A minicomputer. Released in 1969, the HP 2114B is a hard-wired word-addressed 16-bit CPU with a derivative PDP-8 architecture. Its technology consists of SSI TTL integrated circuits and ferrite core memory.

The early HP 2100 series computers are regarded as some of the most reliable computers ever built; systems often ran continuously for years without failure. They also marked the birth of a CPU architecture that would be adapted and utilized in numerous HP computers, calculators and analyzers over the next two decades.

Core Memories: A Photographic History of Early HP Computers
Hewlett-Packard First Generation Computer Census (last update 2016-07-18)

2114B Brochure (PDF)
2114B Price Sheet 06/1970 (PDF)
2114B Price Sheet 05/1971 (PDF)
2114B Volume 1: Specifications and Basic Operation (PDF)
2114B Volume 2: Operation & Maintenance Manual (PDF)
2114B Volume 3: Input/Output System Operation (PDF)
2116 / 2115 / 2114 Absolute Binary Loader Reference Card (PDF)
12618A Synchronous Data Set Interface Kit (PDF)
12539A Time Base Generator Interface Kit (PDF)

Click images to enlarge.

The 2114B featured in this exhibit was rescued from a defunct manufacturing firm in 1996. The computer is in excellent condition and is completely original except for the LED retrofit and line switch replacement described below. The front panel readout exhibits some minor intermittent defects, related to stress wear on the cable leading from the front panel to the CPU.

2006-03-22: Line switch failed and was replaced with nearly identical OEM switch. Front panel retrofitted with quad-die yellow LED panel lamp replacements (T-1 3/4 midget flanged, 24VDC, positive base).

2008-05-19: Computer upgraded with 12618A Synchronous Data Set Interface Kit, card #12621-60001 (receive) and #12622-60001 (transmit).

2014-11-25: Computer upgraded with 12539A Time Base Generator Interface Kit, card #02116-6119, and 12531C Buffered Teleprinter Interface Kit, card #12531-60022.


Hewlett-Packard 2114B Computer, short video of power-on and front panel operation.


2114B, internal details.




2114B, serial number 1105A-00726.


2114B, front panel illumination test.


2114B, protected controls concealed behind a lockable front panel.


2114B, top cover removed, showing the internal layout. Visible in this photo is the Ampex magnetic core memory, F/N 3255877-01 E S/N FA 106 (4,096 words).


2114B, closeup of the card cage.


2114B backplane wiring. Despite the hand-wired appearance, early HP minicomputer backplanes were wired by a complex tape-controlled machine, which took only 3.5 hours to complete a 2116 backplane.


2114B, left side cover removed.


2114B, right side cover removed.


2114B, closeup of core planes.


2114B, switch replacement and lamp retrofit.


2114B, Driver/Switch Card 02114-60427 (A1,2).


2114B, Inhibit Driver Card 02114-60429 (A3).


2114B, Memory Parity Check with Interrupt 12598-6001 (A5).


2114B, Sense Amplifier Card 02114-6005 (A6).


2114B, Arithmetic Logic Card 02114-60424 (A8-11).


2114B, Timing Generator Card 02114-60426 (A12).


2114B, Instruction Decoder Card 02114-60425 (A13).


2114B, Shift Logic Card 02114-6003 (A14).


Copy of A Pocket Guide to HP Computers, originally owned by Homebrew Computer Club alumnus George Morrow (deceased). Computer engineers in Poland used a copy of this publication to construct the prototype MKJ-28 minicomputer, an exact functional clone of the HP 2114B. The subsequent SMC-3 and PRS-4 production models also have full logical conformity with the early 2100-series systems.

HP Computer & Calculator Products (1966-1976)

This article is part of the [Digital Computers] exhibit.

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