[WalterBright]

> a new BASIC interpreter for the 1983 Mattel ECS add-on for Intellivision

Fun fact: Hal Finney (yes, that Hal) wrote a BASIC interpreter for the Intellivision back in 1978 or so in a weekend. It was 2K of code. Mattel shipped it on a cartridge.

ROM space was so tight, the only error message it produced was:

    EH?

Which Hal was very proud of. He showed it to me to make me laugh. At the time I was programming the Mattel Intellivision Roulette cartridge.

[bitwize]

The Level I BASIC for the TRS-80 (which only shipped with 4 KiB of memory originally) had three error messages: WHAT? (syntax errors and the like); HOW? (illegal operations like divide by zero); and SORRY (out of memory).

BootOS, the 512-byte OS written by Oscar Toledo (author of this article), also has a single error message, "Oops".

[blippage]

For anyone interested there's tinybasic, which will run on something as small as an Arduino.

https://github.com/slviajero/tinybasic

[jacquesm]

That's hilarious. I wonder how many corners he cut on that. Is there a disassembly floating around somewhere?

[WalterBright]

It was written in assembly.

I don't know that any listings were kept. It never occurred to me to save any of mine. Oh well.

[jacquesm]

Likewise, I've lost all of my code from the 8 bit era, no big deal, really, but it would have been fun to read some of it.

One of the more interesting projects was to make an annotated listing of the 6809 version of MS Basic for the Dragon 32. We learned so much just by studying that code. It was only 16K and yet we spent months on that.

And for stuff we wrote ourselves, a real-time 3D renderer for simple 3D models in 6502 assembly was probably the pinnacle.

[WalterBright]

I was fortunate to have learned to code in an environment where a lot of excellent programmers were kind enough to help me out. For example, my roommate showed me how stacks worked. It was like magic!

[jacquesm]

For me the big coin drop was arrays. That took a while.

[WalterBright]

For me something similar. I was using lots of if-then for the program logic, and a fellow student showed me how to replace that with an array. Wow!

Another epiphany was when I was reading the source code for ADVENT (the original Adventure game). There was a comment in the listing "A troll is a modified dwarf". And voila! I discovered inheritance.