I saw a guest lecture in my HCI class at CMU this semester from Dan Bricklin [1], who demoed VisiCalc for us on an emulator [2]. One thing that really struck me

I saw a guest lecture in my HCI class at CMU this semester from Dan Bricklin [1], who demoed VisiCalc for us on an emulator [2]. One thing that really struck me was how similar the interface was to today's Excel or Google Sheets. He even demonstrated how a lot of the original shortcuts still worked in Excel. Another fun bit of his talk, about the max digits in VisiCalc: The number of digits that we stored for precision, it was stored as binary-coded decimal, just like a calculator, it was not stored as a binary number. It was stored as the digits, so that it would be exactly the same that you would see on your calculator, without funny round-off errors and stuff like that. But we had to figure out what the maximum number of digits would be. And we decided, let’s - ha-ha. We thought, here us, two little programmers trying to figure out if anyone would use it. Let’s take the budget of the United States of America, in dollars. That’s the maximum, at the time. So that’s the maximum number of digits we had. Sure enough, within a few years, people were using it, according to the Wall Street Journal, for calculating the budget of the United States of America, but only in dollars, not in pennies, because that’s all it could do without going to scientific notation. [1] https://scs.hosted.panopto.com/Panopto/Pages/Viewer.aspx?id=d129250d-7c28-45f5-874b-a9fa01542afb https://scs.hosted.panopto.com/Panopto/Pages/Viewer.aspx?id=... [2] https://www.pcjs.org/apps/pcx86/1981/visicalc/ https://www.pcjs.org/apps/pcx86/1981/visicalc/ [3] http://www.notetakerhd.com/about.html http://www.notetakerhd.com/about.html