Superfast Mandelbrot

[XorA]

Yes, the QDOS screen base address is 131072, which is indeed 20000 in hex.

Not its not always! Thats why you should use an extension to find it properly.

[dilwyn]

Yes, the QDOS screen base address is 131072, which is indeed 20000 in hex.

Not its not always! Thats why you should use an extension to find it properly.

There is some machine code in this little toolkit showing one way of asking the system for screen details. Written as BASIC extensions, but includes source code. It's freeware.

On a BBQL with original Sinclair ROM (only!), you may well find that the screen and system variables stay fixed. On anything else, pretty much anything goes! In other words, make any assumptions and you may well find it works on nothing other than a QL with Sinclair ROMs.

http://www.dilwyn.me.uk/tk/display2.zip

[Derek_Stewart]

or why not find the screen base address in the channel table.

But first the system variables need to be found.

[RWAP]

I wonder how it compares with my own Quick Mandelbrot III - http://www.dilwyn.me.uk/graphics/Quick_ ... ot_III.zip

[Derek_Stewart]

I wonder how it compares with my own Quick Mandelbrot III - http://www.dilwyn.me.uk/graphics/Quick_ ... ot_III.zip

I downloaded the Quick Mandelbrot III, but found I could not unzip the downloaded file in QPC2, SMSQmulator or Q-emulator.

I examined the downloaded zip file, which could be uncompressed with a Linux unzip programme, since the executable had QDOS Header, I unzipped this to a directory.

Q-emulator was configured to point the directory and finally the programme was run, with Minerva in 512x256, Quite nice programme.

I created a floppy disk image:

QuickMandelbrotIII.zip

Quick Mandelbrot III Floppy disk image zipped

(44.93 KiB) Downloaded 157 times

Just unzip the file for the floppy disk image, and point the emulator like sQLux at the file, sQLux needs to 512x256 to run the programme.

Is the source code available?

[dilwyn]

This is precisely why I hate website submissions with executables in QemuLator format, they create more queries than just about anything else (other than zip itself maybe).

Two issues:
1. The paths/filename contains spaces - need to use the "use quoted spaces" option in QDOS zip for this to work.
2. The executable is in QemuLator format (they have the header as a preamble in the file). Only QemuLator (and recent versions of QPC2 which can handle executables in this format) can use this type of zip. Users not familiar with it just assume it's a faulty zip file despite my warnings they're QemuLator files (which of course means nothing to people who haven't used QemuLator).

The subject has been covered plenty of times here in the past.

Thanks to Derek, I'll add this version to my site as a "normal" version now.

[Derek_Stewart]

Hi,

I spent over 30 minutes to get the Quick Mandrlbrot III to run, I wish everyone would use archiving software correctly.

No wonder beginners have problems with all this QDOS Header problems, this only seems to a proliferation of emulators, personally I do not want QL executables with a QDOS Header attached.

Now... back on topic, the speed of both mandelbrot look the same, would timed test bet the best comparison.

[vol]

I wonder how it compares with my own Quick Mandelbrot III - http://www.dilwyn.me.uk/graphics/Quick_ ... ot_III.zip

I downloaded the Quick Mandelbrot III, but found I could not unzip the downloaded file in QPC2, SMSQmulator or Q-emulator.

I have just put all files in folder MDV1 and added two lines to sqlux.cfg

Code: Select all

BOOT_DEVICE = FLP1
DEVICE = FLP1,mdv1/,qdos-like

and all works fine under sQLux.

[vol]

I wonder how it compares with my own Quick Mandelbrot III - http://www.dilwyn.me.uk/graphics/Quick_ ... ot_III.zip

This is a very good program which has much more features than mine. However it is very difficult to compare the performance of both programs.
My program uses a fixed set of parameters. For instance, for the image shown in my initial post (image #12) the next parameters are used:
x is between -1.97 and 0.52;
y is between -1.25 and 1.25;
the iteration count is 37.
The computation does 256x256 dots and this takes 30.2 seconds under sQLux. Sorry, I have not been able to enter the same parameters for QuickMandelbrot III.

[dilwyn]

Hi,

I spent over 30 minutes to get the Quick Mandrlbrot III to run, I wish everyone would use archiving software correctly.

No wonder beginners have problems with all this QDOS Header problems, this only seems to a proliferation of emulators, personally I do not want QL executables with a QDOS Header attached.

Now... back on topic, the speed of both mandelbrot look the same, would timed test bet the best comparison.

Drifting off topic slightly for a moment again, sometimes it just feels to me like every single QL and emulator in existence has a different filing system. Not a problem for those who can find their way around them, but makes it harder (and time consuming) for those like me who try to find a common format that everyone can access to use QL software.

To get back on topic, although I'm not into fractals etc, I'm glad we seem to have another fast Mandelbrot graphics program.