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Re: video segment: where is it?

PostPosted: Thu Dec 28, 2017 8:34 pm
by Trixter
riq wrote:
Trixter wrote:It's good enough for testing. I'm not sure it supports everything 100%, like the 160x100 video mode I invented, but it should work for basic purposes.


Interesting. Did you document the video mode that you discovered somewhere? I would like to try it in the future.


Yes, code is attached. It doesn't work on a Tandy 1000 (there is a blank line every other line) but NewRisingSun found a way to make it work on Tandy 1000 series. Unfortunately I can't find his notes right now, but they're on the web somewhere.

Re: video segment: where is it?

PostPosted: Thu Dec 28, 2017 10:37 pm
by riq
Trixter wrote:Yes, code is attached. It doesn't work on a Tandy 1000 (there is a blank line every other line) but NewRisingSun found a way to make it work on Tandy 1000 series. Unfortunately I can't find his notes right now, but they're on the web somewhere.


Thanks and nice discovery!
I'll search for the Tandy1000 code.

riq wrote:Apparently 0x3da bit 0 works as horizontal retrace... but for some reason, sometimes hangs in part of my code (should double why)


As is often the case, when I blame the hardware, it is usually my code. While converting from Tandy 1000 to PCJr I left a "mov dx,bp" that was causing the crash.
On other new I managed to have a "stable rasterbar" on the PCJr. Not a big deal, but from having a "horiz retrace crashes my machine" to a "stable raster" is a big progress for me :)

Image

It is just a horizontal retrace + nops, and the garbage is not seen since the border covers it.

Re: video segment: where is it?

PostPosted: Fri Dec 29, 2017 1:41 pm
by Trixter
Looks like you did better than I did -- introJR has moving raster bars, but they aren't stable (they have noise).

Re: video segment: where is it?

PostPosted: Fri Dec 29, 2017 9:20 pm
by riq
Trixter wrote:Looks like you did better than I did -- introJR has moving raster bars, but they aren't stable (they have noise).


In case you want to take a look at it here is the code:
https://github.com/c64scene-ar/tandy64/ ... r.asm#L200

I noticed that if the noise is moved too far to the right, it will generate even greater noise (for example: in my code use 340 nops instead of 335 when doing "fat raster bars").
Perhaps that "even greater noise" could be used as a feature instead of a bug... I'll try to find a use for that.