HP 2100

Tens of thousands of machines in the series were sold over its 25-year lifetime, making HP the fourth-largest minicomputer vendor during the 1970s.

[2] All of these models were also packaged as the HP 2000 series, combining a 2100-series machine with optional components in order to run the BASIC programming language in a multi-user time sharing fashion.

[4] HP formed Dynac in 1956 to act as a development shop for projects the main company would not normally undertake.

In 1964, Kay Magleby and Paul Stoft began experimenting with the use of PDP-5 and PDP-8 computers to act as controllers for their complex test systems, but they felt the machines would require changes to truly suit their needs.

Bill Hewlett initially refused to consider the development of a "minicomputer", but when Packard reframed it as an "instrument controller" the deal was approved.

[5] Led by Magleby, the new division completed the design as the 2116A, which was demonstrated 7–10 November 1966 at the Joint Computer Conference in San Francisco.

[7][8] It was one of the earliest 16-bit minis to hit the market, but at the time it was more notable as "an unusual new instrumentation computer" with a highly expandable design and real-time support.

The system launched with 20 different instrumentation cards, including "counters, nuclear scalers, electronic thermometers, digital voltmeters, ac/ohms converters, data amplifiers, and input scanners."

[9] Real-time service was provided by having each card slot be assigned a fixed interrupt vector that called the appropriate device driver.

This led to the introduction of the 2115A in 1967, which removed much of the expansion capabilities to make a lower-cost offering for commercial users.

A further simplified version shipped as the 2114A in 1968,[5] which had only eight slots, leaving room for the power supply to be incorporated into the main chassis.

[10] The 2115 and 2114 also lacked the extensive DMA control of the 2116, removed some of the mathematical operations, and ran at slightly slower speeds.

These are the original models using core memory and a hardwired CPU: In November 1968[13] the company released the 2000A Timeshare System,[13] later known as HP 2000/Access.

This was based on the 2116B (a 2116A with an expanded 8k core memory) running HP Time-Shared BASIC and used a separate 2114 as a terminal server.

These were about twice as fast as contemporary low-cost core, and much smaller, allowing 32kword machines to be built in a 2114-like form factor.

DMS expanded the address format from 15 to 20 bits, allowing a maximum of 1,048,576 words, a dramatic expansion of the original system.

The bit displays on the front panel buttons used small red light-emitting diodes (LEDs), instead of the burnout-prone incandescent bulbs used in earlier versions.

The new L and A series models had HP-IB interface ability, but as with all HP systems at that time, the blinking LED lights were removed from the front panel.

Many companies use real-time operations to take a measurements and control processes—turn on or off a pump, heater, a valve, speed up or slow down a motor, etc.

[26] By 1978, the success of the line had propelled HP to become the fourth-largest manufacturer in the minicomputer space, trailing only DEC, IBM, and Data General.

Additionally, the expansion cards were also equipped with their own processors that allowed them to access main memory and conduct input/output without bothering the CPU.

Although this made the expansion cards incompatible with the earlier models for the first time, it also greatly improved overall performance.

The assembler allows basic mathematical expressions to be written directly, instead of using mnemonics, and also includes a number of pseudo-instructions like ORG to set the base address of the program.

[56] In addition to the assembler and associated linker, the machines initially shipped with a FORTRAN 66 compiler, the operating system, and I/O drivers.

The HP 1000 also was one of the few minicomputers that restricted file names to only five characters, rather than the six common at the time, which made porting and even writing programs a challenge.

The later RTE-A for HP 1000 provided conventional directory structure with 16.4 file names, and made the ru command optional.

The HP 9810, 9820, and 9830 desktop computers use a slow, serialized TTL version of the 2116 CPU, although they did not ultimately use any of the operating system or application software, instead relying on user-friendly ROM-based interpreters, such as BASIC, which work when powered up, and integrated keyboards and displays rather than disks or standard terminals.

[64][65] The BPC was usually packaged in a ceramic hybrid module with the EMC and IOC chips, which added extended math and I/O instructions.

The major differences between the original 2116 architecture and the BPC microprocessor are a completely redesigned I/O structure, the removal of multiple levels of indirect addressing, and the provision of a stack register for subroutine call and return.

Those computers served in power plants, including nuclear ones, other industry, military, at universities, etc., for their high reliability and real-time features.