The more things change, the more they stay the same.
VisiCalc was a product, not a program. Decisions were made with the product in mind and, to the extent possible the programming was towards this end. In practice it was more complicated as we were designing against the limitations of the personal computers, price point and, most important, what the user could understand.
The goal was to give the user a conceptual model which was unsurprising -- it was called the principle of least surprise. We were illusionists synthesizing an experience. Our model was the spreadsheet -- a simple paper grid that would be laid out on a table. The paper grid provided an organizing metaphor for a working with series of numbers. While the spreadsheet is organized we also had the back-of-envelope model which treated any surface as a scratch pad for working out ideas. Since we were used to working with powerful computers without worry about the clock running, we already had the experience of focusing on the users needs rather than the computers needs.
The ability for Dan and I to work as a team was crucial. While he could've written the program, the fact that he wasn't gave him the freedom to focus on what the program should do rather than how to do it. I could appreciate his reasons and would eventually accept that I had to change code that I had labored over. We were able to find ways to take advantage of the limited space available for the program in deciding what features to include or not include.
The original version put the entry area at the bottom of the screen. By playing with this simple prototype Dan found that it was better to put the entry area at the top of the screen and I made the change to the evolving program.
In addition to prototyping, Dan put together a reference card for users. If we couldn't figure out how to explain a feature on the reference card we would change the program. The original method for copying formulas was too complicated so we just changed the design rather than try to explain it.
Tuesday, 20 January 2009
Bob Franklin, who programmed up the first electronic spreadsheet, VisiCalc, in 1978 working with Dan Bricklin -- whose idea it was -- has been writing up the history. I found the following inspirational and salutory. How to build a software product: