Personal Digital Assistant (PDA)

Personal Digital Assistants (PDAs) are handheld computers. They were supposed to be more convenient and simpler than carrying paper. Most significantly, and the reason they are a major invention, is their influence as a bridge to the smartphone.

David Potter created the Psion Organizer in 1984 featuring 2K or RAM in a handheld (sort of programmable) device with a full keyboard. Subsequently, in 1986, Psion released the Mark 2 with a four-line screen. Markedly, the device looked more like a calculator with letter keys than any type of computer. However, it was the first handheld portable computer.

In 1987, Apple started development of the Newton. They shipped the first computer in, labeling the $699 device ($1,250 in 2019) a “personal digital assistant,” in 1993. It was a flop. However, as noted by Wall Street Journal technology reviewer Walt Mossberg at the time, it promised something larger:

“Apple has licensed the Newton software to a variety of other companies which will be building it into their own products — including ‘smart’ phones with screens that feature the pen-based Newton software…”

Walt Mossberg (emphasis added)

The first PDA reasonably priced PDA, that worked well, is the Palm Pilot. Donna Dubinsky and Jeff Hawkins co-founded Palm Inc. in 1992. Before they released their first device they sold the business to modem-maker US Robotics in 1995 for $44 million. The Palm Pilot 1000, priced at $299 ($500 in 2019 dollars), shipped the following year.

Personal Portable Music Player

Battery operated portable personal music players are fun, enabling users to build a cocoon of their own music.

Portable radios and stereos date back to the invention of the transistor. Over time, these grew in size and power. Enormous stereos run from batteries, “boom boxes,” were commonplace. However, boom boxes played music from speakers and one person’s music is another person’s noise.


Eventually, on July 1, 1979, Sony introduced the Walkman TPS-L2, the first portable modern music player. The system featured high-quality headphones and played cassette tapes. Unlike boom boxes, the Walkman was small enough fit in a (large) pocket. At $150 (about $500 USD in 2019). Sony predicted they would sell 5,000 units per month and subsequently sold 50,000 in the first two months. Initially introduced in Japan, the Walkman migrated to the US in June 1980.

The first Walkman ad | The Walkman Archive
Sony’s First Walkman Ad

Sony dominated portable music in the 1980’s, first with their cassette player and later with a DC version. However, due largely to inter-company conflict, Sony lost the market with the introduction of MP3 technology and digital music. In addition to their electronics business, Sony owned a music and movie studio. Unlike prior technology, MP3’s could make an unlimited number of music copies. Executives at the studio reviled MP3’s due to piracy and refused to release a Walkman that supported the popular MP3 format.


There were many MP3 players, the vast majority of them underwhelming. Eventually, on Oct. 23, 2001, Apple released the iPod which supported MP3’s. It was not the first portable MP3 player but was substantially easier to use than competitors. Arguing that piracy was out-of-control as people “shared” pirated music tracks over the internet, Apple convinced the studios to allow the company to sell individual songs for $.99.

Quoting articles from the time:

“The iTunes Music Store may be just the thing to get Apple rocking again too. As everyone knows, it’s been a tough couple of years for the computer industry as well. Apple swung back into the black in the first quarter of 2003 after two quarterly losses, but its profits were only $14 million, compared with $40 million a year ago. And as popular as Apple’s iPod portable MP3 player may be, it contributed less than $25 million of Apple’s $1.48 billion in revenues last quarter. So Jobs is betting that by offering customers ‘Hotel California’ for 99 cents, he can sell not just more iPods but more Macs too.”

Songs In The Key Of Steve Steve Jobs may have just created the first great legal online music service. That’s got the record biz singing his praises. Fortune Magazine. May 12, 2003. (emphasis added)

On Apr. 28, 2003, Apple opened the iTunes Music Store for use with the iPod; in the first week, iTunes customers purchased over a million songs. By 2018, Apple’s quarterly revenue was about $60 billion per quarter.

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Andreas Pavel filed patents for a portable music player, called the Stereobelt, in 1977 but failed to sell the idea to any music company. After protracted litigation ー where Sony won and lost various rounds in different jurisdictions ー Sony paid him a substantial settlement in 2003. Kane Kramer held the first broad patent for portable digital music players but lacked funds to renew it and allowed it to elapse before digital music players became popular.


Spreadsheets simplify calculations and basic database work.


During a lecture at Harvard Business School, in 1978, student Dan Bricklin watched his professor struggle to erase and rewrite cells in a blackboard-based ledger. Thinking about the newly popular Apple II computer Bricklin thought of a better way, a program that allowed users to enter and manipulate numbers.

Bricklin partnered with software engineer Bob Frankston and formed a company on Jan. 2, 1979, to create VisiCalc, the first spreadsheet.

Early reviews raved about the new software:

“Today, virtually the only user of personal computers who is satisfied with the state of the software is the hobbyist. But for the professional, the home computer user, the small businessman, and the educator, there is precious little software available that is practical, useful, universal, and reliable…

Enter Visicalc. What is about to come on the market is a new concept in software that could well go a long way toward fulfilling those aforementioned needs of professionals and alleviating their frustrations… Though hard to describe in words, Visicalc comes alive visually. In minutes, people who have never used a computer are writing and using programs… You simply write on this so-called electronic blackboard what you would like it to do – and it does it.”

Morgan Stanley Electronics Letter, by Benjamin M. Rosen

A Killer App

VisiCalc ran exclusively on the Apple II for years. It was wildly popular. Businesses would buy Apple computers solely to run VisiCalc. Eventually, competing spreadsheet Lotus 1-2-3 addressed many shortcomings of VisiCalc. Sales declined to negligible numbers. Lotus purchased VisiCalc in 1985 and immediately discontinued the program. Subsequently, Microsoft released Excel and, over time, destroyed Lotus 1-2-3 sales, eventually buying the company and shuttering it, much like they did to Bricklin.

“There have been two real explosions that have propelled the industry forward. The first one really happened in 1977, and it was the spreadsheet. I remember when Dan Fylstra, who ran the company that marketed the first spreadsheet, walked into my office at Apple one day and pulled out this disk from his vest pocket and said, ‘I have this incredible new program – I call it a Visual Calculator,’ and it became VisiCalc. And that’s what really drove – propelled – the Apple II to the success it achieved.”

Steve Jobs

Mass Market Microcomputer with Display

The Apple II is the first real mass-market microcomputer. It did anything it was programmed to do, and people programmed it to do all sorts of things. Spreadsheets, invented on the Apple II, drove enormous sales to the business market. The computer also featured several word processors and a sizable game library.

Jobs & Woz

Lifelong friends Steve Jobs and Steve Wozniak liked to hang out together a the Homebrew Computer Club, a California club for do-it-yourself computer enthusiasts. Among other things, the group liked to hack the telephone system to make free long-distance phone calls.

With the release of the MITS Altair computer in January 1975, they realized the potential for a personal microcomputer. The Altair was a terrible machine: the only output was a series of LED lights. However, it sold well; people wanted their own personal computers.

Jobs convinced Wozniak they could build and sell their own personal computer. Wozniak preferred the idea of helping people at the club build computers as a sort of community service. No, Jobs said, this should be a business.

Wozniak worked at Hewitt Packard at the time and needed a release to make a computer. A personal computer, they laughed. Go build your toy. They set up shop in Jobs’ parents garage.

Their first computer, the Apple I, sold a few units. The second computer, the Apple II, was a smash-success that jump-started the personal computer market.

Hippies Storm the Valley

Besides making computers affordable, Apple also introduced a new type of personality into the computer business field. Jobs was an unrepentant hippie. He’d worked at Atari but had no interest in traditional computer science. A college dropout who toured India he didn’t look or act like most of the buttoned-down engineers. Unix developers Dennis Ritchie and Ken Thompson didn’t look the part of engineers but, with their Ivy-League degrees, they had the right background. Jobs was something entirely different.

For years, there was tension in Silicon Valley between Jobs-style software people and traditional engineers. Intel co-founder Gordon Moore was especially annoyed with the impression that anybody could show up and start a computer company. Stories about amateurs successfully hacking operating systems annoyed the Ph.D. engineers. That especially stung because a Ph.D. engineer was the programmer of the first operating system CP/M. Still, there is no denying the creative an artistic flair Jobs and his type brought to the market changed it forever in a positive direction.


The first microcomputer, the Altair 8800, was like a French bulldog. That is, it was ugly, expensive, and not all that bright, but people loved it. The Altair didn’t even have a display, just LED’s that lit up. Most significantly, it served as the inspiration for a small number of future computer entrepreneurs.

The cover of the January 1975 issue of Popular Electronics featured the Altair 8800, the “World’s First Microcomputer,” created by Ed Roberts and his company, MITS. Roberts, an engineer, founded MITS to sell rockets. As the space race fizzled, so too did interest in rocketry and he pivoted to a hot commodity, calculators. Eventually, a price war broke out in calculators so he used the general-purpose Intel 8080 chip, that powered many calculators, to create a first general-purpose home computer.

College students Bill Gates and Paul Allen wrote a BASIC programming language for the popular machine. Gates hacked it out on paper tape. On their way to visit Roberts, they need a company name. Microcomputer Software? Too long. Microsoft. Roberts was happy to sell the program, though he may have been happy to sell anything that ran on his clunky invention.

Lifelong California friends Steve Jobs and Steve Wozniak hung out at the Homebrew Computer Club, for do-it-yourself computer enthusiasts. Jobs worked at Atari and Wozniak at HP. Everybody there noticed the MITS. The two friends were eventually inspired to build their own computer company, Apple.

Roberts eventually sold MITS for $6 million and used the funds to buy a farm then attend medical school. The man called “the father of the personal computer” never again took an interest in computers.

Graphic User Interface

Computers “must be learnable in private… Kindness should be an integral part.”

Alan Kay

The Graphic User Interface (GUI) consists of windows, folders, icons, mice, etc… It enables ordinary people to use computers. Xerox PARC’s GUI vastly simplified computer use and increased productivity by making computers easy and fun to use.

Like the internet itself, it’s difficult to attach a single date on the elements of the Graphical User Interface (GUI).


Engelbart demonstrated many elements of the GUI at the Mother of All Demos. However, Engelbart believed computers should be large and shared. Looking towards the burgeoning mini-computer market, pioneered by Digital Equipment Corp. (DEC), several computer scientists disagreed. Significantly, they thought computers should be personalized, easy-to-use, and fun.

Xerox had one innovation lab, in Rochester near headquarters, focused on copy machines. However, they wanted something far away both figuratively and literally. A lab that could peer into the paper of the future. Subsequently, with a big budget and a sprawling mandate, the Xerox Palo Alto Research Center (Xerox PARC) was created in 1970.

Xerox PARC hired some of the top researchers at the forefront of their field. No sooner did Xerox fund and set-up their experimental lab than several Engelbart researchers, already interested in this field, joined.

Besides the Engelbart staffers, computer scientist Bob Taylor joined Xerox to flesh out the work. Previously, Taylor saw Engelbart’s demo and believed it to be the future of computing. Taylor was a colleague to computer visionary Ivan Sutherland. Another Sutherland student, Alan Kay, also a proponent of an easy-to-use personal computer, joined Xerox PARC.

The GUI is Born

Larry Tesler and Tim Mott wrote the first modern word processor, implementing Engelbart’s copy-and-paste but also adding fonts, what-you-see-is-what-you-get typing, and stateless interaction. The latter innovation markedly simplified typing. Significantly, users need not first tell the computer what you’re trying to do.

Borrowing from SRI’s and Engelbart, and building on Bravo (see above), Tesler wrote a modeless word processor, the Gypsy Word Processor. It implemented a more robust version of copy and paste/cut that looks like what we use today. Subsequently, Tesler left Xerox for Apple in 1980. Dan Ingalls created bit blit, the technology enabling on-screen graphics that has little changed to modern times. Likewise, he also invented pop-up menus. David Smith was an engineer at SRI with Douglas Engelbart. Eventually, at Xerox PARC, he invented user interface icons.

Eventually, Xerox rolled these innovations into the Alto personal computer but never entirely commercialized the Alto. In late 1979, Steve Jobs visited Xerox PARC and took the innovations, and several of the people, back to Apple. Subsequently, they commercialized the work first in the Lisa computer then, eventually, the Macintosh.

Undeniably, Xerox PARC is arguably responsible for more innovations in software than any other single firm in history. However, due to gross incompetence at the managerial level, Xerox made virtually no money.

Xerox Alto Advertisement, 1972
Larry Tesler explains Steve Jobs visit,
“Everything cool going on at Xerox PARC”

Personal Computer, Xerox Alto (the “interim Dynabook”)

Dynabook was at the heart of Xerox PARC. Eventually realized as the Xerox Alto, it is essentially the first personal computer. Easy-to-use with a graphical interface, what-you-see-is-what-you-get (WYSISYG) programs, icons, the mouse, networking. Everything we take for granted today started as the Dynabook/Alto.


The Dynabook dates to Kay’s doctoral thesis and the first interview with Xerox. It is the underlying principle behind much of the work at Xerox PARC.

Kay envisioned a computer for just one person. His theoretical computer notebook would cost less than $500 “so that we could give it away in schools.” Compactness was important so “a kid could take it wherever he goes to hide.” Programming should be easy: “Simple things should be simple, complex things should be possible.” “A combination of this ‘carry anywhere’ device and a global information utility such as the ARPA network or two-way cable TV will bring the libraries and schools (not to mention stores and billboards) to the home.”

Xerox refused to fund the Dynabook, it was an inappropriate project since Xerox PARC was for offices, not children. Subsequently, Kay ignored them, sneaked away and, with the help of Thacker and Lampson, built what became the Alto. Kay referred to the Alto as “the interim Dynabook.”

Xerox: Computers Won’t Make Money

When finished, in 1973, Kay released it with a graphic of Cookie Monster, from Sesame Street, holding the letter C. Xerox built about 2,000 Alto’s for company use but never fully commercialized the computer. A Xerox executive told Taylor “the computer will never be as important to society as the copier.” The Dynabook, the personal computer, did not add shareholder value.

As of mid-2019, Xerox is worth $6.5 billion. Microsoft is worth $1.01 trillion. Apple is worth $874 billion.

Of course, Steve Jobs eventually visited Xerox PARC and rolled many ideas of the Alto into an Apple computer first called the Lisa and, later, the Macintosh. Soon after, Microsoft released Windows that looks suspiciously similar.


Touch screens existed in science fiction long before they entered the real-world. Star-Trek: The Next Generation made extensive use of what today are modern touch screens decades before they became common.

Johnson described the touch screen in a seminal paper. Johnson himself never actually created nor patented a touch-screen. Sam Hurst at the U. of KY developed a touch screen sensor in 1971 though it was not see-through until 1974.

The first real touch-screen, with a screen visible behind the touch, was used on Bitzer’s PLATO system, deployed in 1972. PLATO used infrared beams and detected when they were broken rather than more modern systems that detect a screen touch.

In 1983, HP released the HP-150, the first touchscreen computer. BellSouth released the first touchscreen phone, the Simon Personal Communicator, in 1993. By the mid 2000s touchscreens were becoming more mainstream. Finally, with the introduction of Apple’s iPhone in 2007, touchscreens started on the path towards commonplace tech.

Hurst, the early touchscreen pioneer, went on to found a successful touchscreen company, Elographics (now Elo Touch).