Hacker News Reader

Comment by crazygringo | Hacker News Reader

I made quite a sophisticated viewer as a teen, but boy was it slow to run back then, back on a 486.

Now people write viewers that run lighting fast in a browser thanks to WebGPU! Like:

https://www.reddit.com/r/fractals/comments/o7l4bm/please_try...

I remember as a teen I did mine in 68000 assembly on a Commodore Amiga to get it reasonable fast considering it was running on a 16 MHz CPU — i would say a few seconds to draw the canonical image — but IIRC it reached pretty fast the limit of math precision.

At that time I didn't know what was a complex number, but was fascinated by the whole concept of fractals and how complex structures could be created with a relative simple program.

A few seconds? Wow! I did a science fair project on the Mandelbrot set using my Amiga 2000, and it took me a good 45+ minutes to generate a single 320x200 color image. IIRC, I wrote the generator in some variant of Pascal, and was so happy with the performance increase over Basic on my C=128...

I ran in to the precision limit pretty quickly, same as you. I didn't understand computers well enough to know that's what the problem was, and I remember spending hours pouring over my code, trying to figure out where the bug was. Good times. :D

The difference is probably you used floats and he/she used fixed point (integers). Of course that way you do run out of precision very quickly.

Software emulated floats on Amiga 2000 were really, really slow.

If I'm not confusing it with something else, I seem to recall that when zooming on the set the calculation was nearly instantaneous. As you said, good times! ^__^

I still have that A500 but who knows where I put those floppies, I'm tempted to turn it on but I'm scared the PSU will blow itself...

A500 PSUs (particularly the 2nd one) are the most reliable and powerful.

The A500 themselves are built like tanks. Chances are it just works.

But watch out for trapdoor expansion. Most likely has a varta barrel battery in it, which will eventually leak and damage the expansion, and possibly also the computer itself.

I would recommend opening that trapdoor and removing/inspecting anything installed there as soon as possible.

These barrel batteries are only used to keep RTC, and the board will be fine w/o.

I typed in a BASIC program for a C-64 from a computer magazine. That was a popular mechanism for software distribution back then.

I thought "this will never work", but I was amazed that it did in fact work. I remember letting it run overnight to find a complete 160x200 4-color image the next morning. Just clearing the screen using a loop to fill 8192 bytes with 0s took over a minute.

Everything about the computers at the time was so terrible, I don't feel any nostalgia for those days or that technology.

The one I wrote in BASIC on my Apple IIe never finished, it hadn't even got the interesting bits of the set after a day or so and I needed to play games.

FRACTINT was great because I could use my 286 and it was fairly fast because used integer whenever possible.

I did it in QuickBasic (also on a 486).

Now that's slow.

Reply on news.ycombinator.com