VisiCalc

VisiCalc (for "visible calculator") was the first spreadsheet computer program for personal computers, originally released for Apple II by VisiCorp in 1979. It is often considered the application that turned the microcomputer from a hobby for computer enthusiasts into a serious business tool, prompting IBM to introduce the IBM PC two years later. VisiCalc is considered to be Apple II's killer app. It sold over 700,000 copies in six years, and as many as 1 million copies over its history.

Initially developed for the Apple II computer using a 6502 assembler running on the Multics time sharing system, VisiCalc was ported to numerous platforms, both 8-bit and some of the early 16-bit systems. In order to do this, the company developed porting platforms that produced bug compatible versions. The company took the same approach when the IBM PC was launched, producing a product that was essentially identical to the original 8-bit Apple II version. Sales were initially brisk, with about 300,000 copies sold.

VisiCalc used the A1 notation in formulas.

When Lotus 1-2-3 was launched in 1983, taking full advantage of the expanded memory and screen of the PC, VisiCalc sales ended almost overnight. Sales declined so rapidly, that the company was soon insolvent. Lotus Development purchased the company in 1985, and immediately ended sales of VisiCalc and the company's other products.

History
Dan Bricklin conceived VisiCalc while watching a presentation at Harvard Business School. The professor was creating a financial model on a blackboard that was ruled with vertical and horizontal lines (resembling accounting paper) to create a table, and he wrote formulas and data into the cells. When the professor found an error or wanted to change a parameter, he had to erase and rewrite several sequential entries in the table. Bricklin realized that he could replicate the process on a computer using an "electronic spreadsheet" to view results of underlying formulae.

Bob Frankston joined Bricklin at 231 Broadway, Arlington, Massachusetts, and the pair formed the Software Arts company, and developed the VisiCalc program in two months during the winter of 1978–79. Bricklin wrote:

Bricklin was referring to the variety of report generators that were in use at that time, including Business Planning Language (BPL) from International Timesharing Corporation (ITS) and Foresight from Foresight Systems. However, these earlier timesharing programs were not completely interactive, and they pre-dated personal computers.

Frankston described VisiCalc as a "magic sheet of paper that can perform calculations and recalculations", which "allows the user to just solve the problem using familiar tools and concepts". The Personal Software company began selling VisiCalc in mid-1979 for under $100, after a demonstration at the fourth West Coast Computer Faire and an official launch on June 4 at the National Computer Conference. It required an Apple II with 32K of random-access memory (RAM), and supported saving files to magnetic tape cassette or to the Apple Disk II floppy disk system.

VisiCalc was unusually easy to use and came with excellent documentation; Apple's developer documentation cited the software as an example of one with a simple user interface. Observers immediately noticed its power. Ben Rosen speculated in July 1979, that "VisiCalc could someday become the software tail that wags (and sells) the personal computer dog". For the first 12 months, it was only available for Apple II, and it became that platform's killer app. The computer was sold, John Markoff wrote, as a "VisiCalc accessory"; many bought $2000 Apples to run the $100 software — more than 25% of those sold in 1979 were reportedly for VisiCalc — even if they already owned computers. Steve Wozniak said, that small businesses, not the hobbyists he and Steve Jobs had expected, purchased 90% of Apple IIs. Apple's rival Tandy Corporation used VisiCalc on Apple IIs at their headquarters. Other software supported its Data Interchange Format (DIF) to share data. One example was the Microsoft BASIC interpreter supplied with most microcomputers that ran VisiCalc. This allowed skilled BASIC programmers to add features, such as trigonometric functions, that VisiCalc lacked.

Bricklin and Frankston originally intended to fit the program into 16k memory, but they later realized that the program needed at least 32k. Even 32k was too small to support some features that the creators wanted to include, such as a split text/graphics screen. However, Apple eventually began shipping all Apple IIs with 48k memory following a drop in RAM prices, which enabled the developers to include more features. The initial release supported tape cassette storage, but that was quickly dropped.

At VisiCalc's release, Personal Software promised to port the program to other computers, starting with those that used the MOS Technology 6502 microprocessor, and versions appeared for Atari 800 and Commodore PET, both of which could be done easily, because those computers used the same processor as Apple II, and large portions of code could be reused. The PET version, which contained two separate executables for 40 and 80-column models, was widely criticized for having a very small amount of worksheet space due to the developers' inclusion of their own custom DOS, which used a large amount of memory (the PET only had 32k versus Apple II's available 48k).

Other ports followed for Apple III, the Zilog Z80-based Tandy TRS-80 Model I, Model II, Model III, Model 4, and Sony SMC-70. The TRS-80 Model I and Sony SMC-70 ports were the only versions of VisiCalc without copy protection. The Sony SMC-70 port was the only CP/M version. Most versions were disk-based, but the PET VisiCalc came with a ROM chip that the user had to install in one of the motherboard's expansion ROM sockets. The most important port was for the IBM PC, and VisiCalc was one of the first commercial packages available when the IBM PC shipped in 1981. It quickly became a best-seller on this platform, in spite of being severely limited in order to be compatible with the versions for the 8-bit platforms. It is estimated, that 300,000 copies were sold on the PC, bringing total sales to about 1 million copies.

By 1982, VisiCalc's price had risen from $100 to $250. Several competitors appeared in the market, notably SuperCalc and Multiplan, each of which added more features and corrected deficiencies in VisiCalc, but could not overcome its market dominance. A more dramatic change occurred with the 1983 launch of Lotus Development Corporation's Lotus 1-2-3, written by former Personal Software/VisiCorp employee Mitch Kapor, who had written VisiTrend and VisiPlot. Unlike the PC version of VisiCalc, 1-2-3 was written to take full advantage of the PC's increased memory, screen and performance. Yet it was designed to be as compatible as possible with VisiCalc, including the menu structure, to allow VisiCalc users to easily migrate to 1-2-3.

1-2-3 was almost immediately successful, and by 1984, InfoWorld wrote that sales of VisiCalc were "rapidly declining", stating, that it was "the first successful software product to have gone through a complete life cycle, from conception in 1978 to introduction in 1979 to peak success in 1982 to decline in 1983 to a probable death according to industry insiders in 1984." The magazine added, that the company was slow to upgrade the software, only releasing an Advanced Version of VisiCalc for Apple II in 1983, and announcing one for the IBM PC in 1984. By 1985, VisiCorp was insolvent. Lotus Development acquired Software Arts, and ended sales of the application.

Releases
1979: Apple II

1980: Apple III, TRS-80 Model III, Apple II, IBM PC, TRS-80 Model 2, Commodore PET CBM-80, HP 125, Atari 800

1981: IBM PC, Sony SMC-70

1982: Apple III, Apple IIe—VisiCalc Advanced Version

1983: Enhanced VisiCalc for TRS-80 Model 4, Model II (with RAM expansion card) and Model 16. Used banked memory beyond the base 64 KB.

Reception
In 1983 Softline readers named VisiCalc tenth overall and the highest non-game on the magazine's Top Thirty list of Atari 8-bit programs by popularity. II Computing listed it second on the magazine's list of top Apple II software as of late 1985, based on sales and market-share data.

In its 1980 review, BYTE wrote "The most exciting and influential piece of software that has been written for any microcomputer application is VisiCalc". It concluded, "VisiCalc is the first program available on a microcomputer that has been responsible for sales of entire systems". Creative Computing 's review the same year similarly concluded, "for almost anyone in business, education, or any science-related field it is ... reason enough to purchase a small computer system in the first place". Compute! reported, "Every Visicalc user knows of someone who purchased an Apple just to be able to use Visicalc". Antic wrote in 1984, "VisiCalc isn't as easy to use as prepackaged home accounting programs, because you're required to design both the layout and the formulas used by the program. Because it is not pre-packaged, however, it's infinitely more powerful and flexible than such programs. You can use VisiCalc to balance your checkbook, keep track of credit card purchases, calculate your net worth, do your taxes—the possibilities are practically limitless." The Addison-Wesley Book of Atari Software 1984 gave the application an overall A+ rating, praising its documentation and calling it "indispensable ... a straight 'A' classic".

In 1999, Harvard Business School put up a plaque commemorating Dan Bricklin in the room where he had studied. It read "Forever changed how people use computers in business."

In 2006, Charles Babcock of InformationWeek wrote that, in retrospect, "VisiCalc was flawed and clunky, and couldn't do many things users wanted it to do”, but also, “It's great because it demonstrated the power of personal computing.”