Technology History | Loveland, Colorado — The Advertisement That Said Personal Computer

An advertisement in Science on 4 October 1968 called the machine a personal computer, which is among the earliest recorded uses of the phrase in print.

The machine was the HP 9100A, and Hewlett-Packard sold it as a calculator deliberately.

The reason HP gave afterwards was commercial rather than technical: a customer's computer department would have rejected anything labelled a computer that did not look like an IBM.

It started in an apartment. Tom Osborne, a Berkeley-trained engineer, built a floating-point calculator into a balsa wood case finished with green automotive touch-up paint and called it the Green Machine.

He showed it to several companies without interest before HP looked at it in 1965.

Development began that year at HP Laboratories in Palo Alto and moved at the prototype stage to this campus, the Loveland division, which finished the design and manufactured it.

More than one person's work went in. A prototype by Malcolm McMillan handled transcendental functions, Arndt Bergh and Chuck Near were developing read-only memory, and Osborne's design supplied the floating-point arithmetic.

What shipped in March 1968 weighed forty pounds and cost around $4,900.

It had a small cathode-ray display showing three registers and a reader that took magnetic cards the size of a credit card.

Its processor contained no integrated circuits whatsoever. Early ICs drew too much power, so the logic was assembled from discrete transistors.

Whether this was the first personal computer needs handling with care.

Olivetti's Programma 101 reached buyers in 1965 and has its own supporters, and the machines that fixed the term in ordinary use arrived a decade later.

What the 9100A can be credited with exactly is the phrase in print, and a desktop machine a scientist could keep and program without booking time from a computer department.

HP began building in Loveland in February 1960 and had 28 people working in a 12,800 square foot building by that July. The HP Computer Museum's history records it as the first large electronics firm to put a plant in Colorado.

Building A at 815 Fourteenth Street Southwest opened in October 1962, and the division went on to make calculators, printers and voltmeters.

The site passed to Agilent when HP separated its instrument business at the end of the 1990s, and Agilent had largely left by 2007.

In 2011 the developer Cumberland and Western bought the 170-acre campus from the City of Loveland for $5 million in cash and renamed it the Rocky Mountain Center for Innovation and Technology.

It is a fenced private technology park with controlled access points, so this is a drive-past rather than a visit.

The cover photograph shows an HP 9100A on display at a Vintage Computer Festival.

Photo: Michael Holley, public domain, via Wikimedia Commons.