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Completing a BASIC language interpreter in 2025

nanochess.org

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Re: Completing a BASIC language interpreter in 2025

#11

Post by jacquesm »

WalterBright wrote: post #9

> 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…

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

Re: Completing a BASIC language interpreter in 2025

#12

Post by bitwize »

WalterBright wrote: post #9

> 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…

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".

Re: Completing a BASIC language interpreter in 2025

#13

Post by Razengan »

zahlman wrote: post #6
Razengan wrote: post #2

Ah the Aquarius :) My uncle got one as a donation to his private little "museum" and all I remember was how different it looked from the other machines of that era and a game that taught you spelling by shooting down letters Space Invaders style.

> a game that taught you spelling by shooting down letters Space Invaders style. Sure it wasn't meant to teach typing ? (Maybe I'm thinking of a different game...)

Oh yes maybe typing, same thing to me ^^

Re: Completing a BASIC language interpreter in 2025

#14

Post by nobody_special »

I wrote a BASIC interpreter that supported integers and strings circa 1979. Written in assembly, it used a simple precedence parser. I measured its CPU utilization under cpu-intensive loads: ~9.5% for lexical/token analysis, ~20% for the parser, and ~69.5% for semantic work.

It was a lot of fun. The assembler I used was really powerful; I used its macro facilities to create ‘rule’ macros that defined the BNF of the language.

Congrats on your own implementation!

Re: Completing a BASIC language interpreter in 2025

#15

Post by nanochess »

kragen wrote: post #7

Very impressive, as usual! I've never written a 100-page assembly program in my life, much less in one month. The string stack part reminded me of http://turboforth.net/downloads/docs/ANS_String_Lib.pdf , with the same motivation of handling string expressions in limited memory without needing a GC.

First time I heard of it. I should know better as the TI-99/4A forum is just one click away from the Intellivision forum. Thanks for the heads up!

Re: Completing a BASIC language interpreter in 2025

#16

Post by WalterBright »

jacquesm wrote: post #11
WalterBright wrote: post #9

> 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…

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

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.

Re: Completing a BASIC language interpreter in 2025

#17

Post by jacquesm »

WalterBright wrote: post #16
jacquesm wrote: post #11

Earlier quoted context omitted.

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

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.

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.

Re: Completing a BASIC language interpreter in 2025

#18

Post by kragen »

nanochess wrote: post #15
kragen wrote: post #7

Very impressive, as usual! I've never written a 100-page assembly program in my life, much less in one month. The string stack part reminded me of http://turboforth.net/downloads/docs/ANS_String_Lib.pdf , with the same motivation of handling string expressions in limited memory without needing a GC.

First time I heard of it. I should know better as the TI-99/4A forum is just one click away from the Intellivision forum. Thanks for the heads up!

I'm delighted to have been of service!

Re: Completing a BASIC language interpreter in 2025

#19

Post by WalterBright »

jacquesm wrote: post #17
WalterBright wrote: post #16

Earlier quoted context omitted.

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.

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 i…

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!

Re: Completing a BASIC language interpreter in 2025

#20

Post by jacquesm »

WalterBright wrote: post #19
jacquesm wrote: post #17

Earlier quoted context omitted.

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 i…

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!

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