Lisp Machine Manual (1984)

I don't care for Scheme, but I'd be very, very surprised if it'd have failed in such a situation. If a terrible train wreck of a language like JavaScript can succeed, pretty much anything better than INTERCAL can. People wanted to extend browsers; had Scheme been the only way to do that, Scheme is what they'd have used.

Instead of making disparaging remarks about people's mental health, learn some basic parsing theory:

https://en.wikipedia.org/wiki/Context-sensitive_grammar

I don't think awareness of Lisp was evenly distributed among people developing on PCs in the time period when the network advantage was obtained. Even if it was, if there were already a decent C compiler, I don't think most practical engineers would immediately embark on a compiler development project. During this era, those who did know about Lisp certainly would have regarded it as being too resource-intensive for work in a resource-constrained environment like the PC.

I think it's specious to say it's easy to develop a simple Lisp compiler, so why didn't anything get ported. The code you may have wanted to port would not have been written in some minimalist dialect of Lisp, it would have been written in ZetaLisp. So there would be assumptions about resources and the underlying system that you would have to fake. And again, we're talking about porting from a resource-rich environment to a resource-scarce environment.

It was probably a reach for me to say there wasn't anything to port. But what would someone have wanted to port? A graphical application that ran on a Lisp machine would have made assumptions about the display that aren't true about a PC. An academic AI program would have been too short on resources to be much use.

What wound up selling the PCs in the early days was business applications. Were there an assortment of useful business applications on Lisp machines that there was commercial demand for? WordStar and Visicalc invented that territory and were first released in the late 70s—does anyone remember programs for the Lisp machine that businesses were clamoring for? And really, software churn has always meant there are more new programs in use than old ones.

What I don't have an explanation for is why the C compilers produced better code than the Pascal compilers. Partly, I know p-code made it faster to build a Pascal compiler but I don't know why it inhibited development of more performant ones. Turbo Pascal's speed of compilation was a result of not having an AST, which probably inhibited performance optimizations, but that may have been too late in the story to explain anything. And I don't have an explanation for why nobody developed a Lisp-like language that had explicit allocation. My best guess would be simply that their attention was elsewhere, probably working on AI, which wouldn't bottom out until after the winners were already entrenched.

By the way, in case it isn't clear, I am really enjoying this conversation. I'm very interested in this window of time in computing and if I have a wrong idea about something, I do want to know. The only way to preserve this history is to talk about it and keep the memory alive.

The PDP-11 was in no way compatible with the PDP-10, and there was no way a PDP-10 Lisp implementation like Maclisp or Interlisp would fit on a PDP-11. All you have to do is Google "PDP-11 Lisp" to see that there were many different Lisp interpreters and at least one compiler implemented for the PDP-11 throughout the 1970s. Likewise Intel processors - the first implementation of Lisp on the 8080 was done by Takashi Chikayama (http://www.logos.ic.i.u-tokyo.ac.jp/~chik/) in 1976 (http://www.softwarepreservation.org/projects/LISP/utilisp/ut...)

My assertion is that you're looking at the wrong decade for C's network effects. You should be looking at the PDP-11 decade, not the PC decade. And in the PDP-11 decade, I believe there was much wider awareness of Lisp. (I was a kid then, so that's just my impression. I don't actually know.)

> It was probably a reach for me to say there wasn't anything to port. But what would someone have wanted to port? A graphical application that ran on a Lisp machine would have made assumptions about the display that aren't true about a PC. An academic AI program would have been too short on resources to be much use.

Fair point.

> And I don't have an explanation for why nobody developed a Lisp-like language that had explicit allocation.

Lisp allocates all the time. You have to work hard if you want it not to. So if you want explicit allocation, you'd have to invoke it all the time, and it would really get in the way - far more than it does in C. (Far more things are allocated in Lisp than in C.)

But you could mean "why didn't someone make a Lisp where you could explicitly allocate a block of memory if you chose to"? You wouldn't have to always use it in that case, so my objection in the previous paragraph doesn't apply. But if you did that, first, the garbage collector would have to know how to clean up those objects (or else you'd have to explicitly free them), and second, you'd have to be able to do something with it. Lisp, to my (very limited) knowledge, doesn't have a way to treat an allocated block of memory as anything other than a cons pair. You'd have to add that to the language. You could do it, but it would be something tacked on to the side of the language, not something you could use the same as the rest of the language.