VisiCalc Reconstructed • Hacker News Board

Re: VisiCalc Reconstructed

#41

Post by WillAdams » Fri, Mar 20, 2026, 6:30 PM UTC

wslh wrote: post #38

fouronnes3 wrote: post #26

Very cool article! I also implemented a spreadsheet last year [0] in pure TypeScript, with the fun twist that formulas also update backwards. While the backwards root finding algorithm was challenging, I also found it incredibly humbling to discover how much complexity there is in the UX of the simple spreadsheet interface. Handling selection states, reactive updates, detecting cycles of dependency and gracefully rec…

The idea of backward updating is fascinating but is not generally feasible or computable. What kind of problems can you solve backwardly?

I implemented bi-directional solving in a very simple "Proportion Bar" app --- sort of --- one side would calculate at the specified scaling factor (so 100% could do unit conversions), the other would calculate the scaling factor necessary to make the two sides agree.

Re: VisiCalc Reconstructed

#42

Post by WillAdams » Fri, Mar 20, 2026, 6:36 PM UTC

breadsniffer wrote: post #16

Anyone know what kind of departments/parts of business were the first adopters of visicalc?

One of my most vivid memories from childhood was being in a computer store which sold Apple ][s when a gentleman drove up in an (awesome) black Trans Am and declared to the salesperson, "I want a Visicalc" --- after explaining that it was a computer application and that the potential customer didn't have an Apple, the salesperson proceeded to put together pretty much my dream machine (at the time), an Apple ][ w/ dual-disk drives and 80 col. card and green display and 132 col. dot matrix printer, and of course, a copy of Visicalc.

After paying by writing out a check, I helped load everything into his car and he drove off into the sunset --- I was then allowed to choose a reformatted disk from the box as a reward and chose _The Softporn Adventure_ (which I then stupidly removed the label from, but it wasn't something I wanted to explain to my parents...).

Re: VisiCalc Reconstructed

#43

Post by 4leafclover » Fri, Mar 20, 2026, 6:50 PM UTC

Very nice read!

Though I think the definition of the parser struct should be

  struct parser {
    const char* s;
    const char* p;
    struct grid* g;
  };

based on the rest of the code.

Re: VisiCalc Reconstructed

#44

Post by rnxrx » Fri, Mar 20, 2026, 7:06 PM UTC

This a great article - both interesting and potentially really useful to folks teaching- or learning- programming.

Re: VisiCalc Reconstructed

#45

Post by somat » Fri, Mar 20, 2026, 7:14 PM UTC

wslh wrote: post #38

fouronnes3 wrote: post #26

Very cool article! I also implemented a spreadsheet last year [0] in pure TypeScript, with the fun twist that formulas also update backwards. While the backwards root finding algorithm was challenging, I also found it incredibly humbling to discover how much complexity there is in the UX of the simple spreadsheet interface. Handling selection states, reactive updates, detecting cycles of dependency and gracefully rec…

The idea of backward updating is fascinating but is not generally feasible or computable. What kind of problems can you solve backwardly?

I am not sure if I know what I am talking about or if it counts in this scenario but constraint solvers come to mind. I am mainly familiar with them in a CAD context so I am struggling to think of a use for them in a spreadsheet context. But I think being able to say given these endpoints find me some values that fit could be a very valuable tool.

But like I said I am not sure that I know what I am talking about and I may be confusing backwards calculation with algebraic engines. I would love for algebra solvers to be a first class object in more languages.

Re: VisiCalc Reconstructed

#46

Post by jdswain » Fri, Mar 20, 2026, 7:19 PM UTC

khazhoux wrote: post #17

I’m genuinely worried that we’re the last generation who will study and appreciate this craft. Because now a kid learning to program will just say “Write me a terminal spreadsheet app in plain C.”

Which is somewhat akin to downloading one today. If, however, that same kid started small, with a data model, then added calculation, and UI and stepped through everything designing, reviewing, and testing as they went, they would learn a lot, and at a faster pace than if they wrote it character by character.

Re: VisiCalc Reconstructed

#47

Post by btilly » Fri, Mar 20, 2026, 7:20 PM UTC

wslh wrote: post #38

fouronnes3 wrote: post #26

Very cool article! I also implemented a spreadsheet last year [0] in pure TypeScript, with the fun twist that formulas also update backwards. While the backwards root finding algorithm was challenging, I also found it incredibly humbling to discover how much complexity there is in the UX of the simple spreadsheet interface. Handling selection states, reactive updates, detecting cycles of dependency and gracefully rec…

The idea of backward updating is fascinating but is not generally feasible or computable. What kind of problems can you solve backwardly?

While the general problem is not always tractable, some of the special cases are pretty important.

Take, for example, backprop in machine learning. The model operates forwards. Then you solve backwards to figure out how to update the terms.

Re: VisiCalc Reconstructed

#48

Post by OliverM » Fri, Mar 20, 2026, 7:31 PM UTC

airstrike wrote: post #23

OliverM wrote: post #19

Earlier quoted context omitted.

Isn’t the existence & success of visicalc a direct counter to this?

Is anyone using visicalc today? I'm not sure how its past success, however fantastic, can be translated into "a dependency graph is often an overkill for a spreadsheet"

The clause "it's absolutely necessary for all but the simplest toy examples" is what I was disagreeing with. But I wouldn't be surprised to hear that visicalc adopted one as soon as it was technically feasible in later versions.

Re: VisiCalc Reconstructed

#49

Post by somat » Fri, Mar 20, 2026, 7:43 PM UTC

hunter4309 wrote: post #20

bonsai_spool wrote: post #2

Are there good command-line interfaces for spreadsheets? I don't do anything super financially-important and I'd prefer to stay in the terminal for quick editing of things, especially if I can have Vi keybindings.

Visidata[0] is a killer data swiss army knife. It's even inspired off Visicalc [0] https://www.visidata.org/

It's weird but visidata is my favorite spreadsheet.

"But... visidata is not a spreadsheet"

I know, that's what makes it so weird.

On contemplation, I think I grew dissatisfied with the normal spreadsheet data model, I wanted something bettered structured than the "it's a big bag of cells" that spreadsheets present, I wanted row security. The best I found was the relational database. I currently use a local postgres db for most things I would have used a spreadsheet for. The interfaces sort of suck in comparison but at least I have sane data structures.

Re: VisiCalc Reconstructed

#50

Post by airstrike » Fri, Mar 20, 2026, 8:06 PM UTC

OliverM wrote: post #48

airstrike wrote: post #23

Earlier quoted context omitted.

Is anyone using visicalc today? I'm not sure how its past success, however fantastic, can be translated into "a dependency graph is often an overkill for a spreadsheet"

The clause "it's absolutely necessary for all but the simplest toy examples" is what I was disagreeing with. But I wouldn't be surprised to hear that visicalc adopted one as soon as it was technically feasible in later versions.

visicalc is not the benchmark you think it is. it's decades old. this day and age, dependency graphs for any real world use case will definitely need a dependency graph. it helps no one to suggest otherwise, and actually makes light of a specific engineering task that will for a fact be required of anyone looking to build a spreadsheet engine into a product