In the replies underneath, someone ran it on a real Acorn Electron computer (6502 at 1 MHz), where it completed in 8 hours and 40 minutes. Not too bad really.
I'm running this on a BBC micro emulator running at period-accurate speed, and it's taking just under a minute to draw one line. So I think it's going to finish in about 4 hours, which would make sense - approximately twice as fast as the Acorn Electron.
The Electron runs extra slowly in MODE 1 as the video system needs 100% of the RAM bandwidth to form the display. The CPU essentially ends up paused during the visible portion of each scan line, so the effective speed is probably more like 0.6 MHz.
Intel's optimization manual has suggestions for fast versions at 15.12.3 (recommended by @James https://stackoverflow.com/a/2637823/10981777) Don't look especially long to implement for 22-bit approximation.
Thanks. So much more of that code makes sense now. IFD, SGNU, FORN, FORM. FORM especially. So many codes now have the word FORM as a special word.
What a nightmare to read though if you don't know what it's supposed to be written like. Is it a: "FORM=" or a "FOR M=" ? Is it: "S GNU:G", "SG NU:G", "SGN U:G"? SQRD totally looks like some special kind of square root implementation.
Yeah, early BASICs tended to let you skip the spaces, and in fact it sometimes did have a measurable effect on parsing/execution speed. And of course on file size too… Additionally, at least C64 Basic had two-character shorthands for all keywords.
I recreated a mandlebrot zoom I saw in a library book in bbc basic and the last image took two weeks. I had 8 of them saved on a floppy and that would slideshow them for a 2fps "movie"
all the basics i used on processors that slow were surprisingly inefficient, even for an interpreted languages
i thought they had to be, running on processors with that little memory. though later on i learned about forth, which is surprisingly efficient for an interpreted language
a more likely explanation is that sophie wilson was just a better hacker than bill gates and paul allen
Yeah, BBC BASIC is really good. Both the language design and the implementation.
I loved it at the time, and the more I think back on it the more impressed I am. Like it had a very decent suite of floating-point routines, which if I remember right were very performant. In a 32KB ROM!
Some of the improvement in BBC BASIC over Microsoft's BASIC is attributable to the larger ROM(the first Altair BASIC was just 4k), but it's also that the BBC Micro's 6502 and DRAM was clocked higher than contemporaries. It's just a faster, more refined 8-bit machine all around.
Some good discussion of that on The BBC BASIC wiki entry: https://en.wikipedia.org/wiki/BBC_BASIC (paragraph beginning "Due to a number of optimizations[…]".
Because BBC Basic had a built-in assembler it was pretty uncommon for BBC programs to inline machine code as raw data (unlike some other computers from BITD).
