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Re: Developing new ZX81 Video Driver
Posted: Tue Jun 01, 2010 6:51 pm
by pterodactyl
I was wondering can I use this to display some non-standard characters- like music notes or graphics for a ZX-81 MIDI app I'm working on?
I guess I'll need to become one with the code....
Re: Developing new ZX81 Video Driver
Posted: Mon Jun 07, 2010 6:04 pm
by thewiz
Hi pterodactyl,
Its not going to give you pseudo hi-res, which is what you would need. However it should be possible to create a version of this driver that gives pseudo hi-res instead of normal characters.
Cheers
Re: Developing new ZX81 Video Driver
Posted: Wed Oct 13, 2010 7:44 pm
by Paul
Hi,
last post was quite some time ago, any news?
Is it possible to have different display sizes for differnt time for own loops?
Cheers
Paul
Re: Developing new ZX81 Video Driver
Posted: Sat Oct 16, 2010 6:46 pm
by thewiz
Hi Paul,
Since I last posted I started a 10 week contract which meant no time to play on the Zeddy. And to be honest, there didn't seem to be much interest in such a driver either. Thats not to say its dead, but my Z80 skills are not quite up to writing a 16Kb game using it. I did start converting Gridrunner and am hoping to get time to finish that soon.
In answer to your question, you can set the number of lines to display per frame. In fact you can set number of lines for each alternative frame. The max number of lines is still 24. Hope that answers your question?
Regards
thewiz
Re: Developing new ZX81 Video Driver
Posted: Wed Jun 03, 2020 2:59 pm
by kmurta
thewiz wrote: ↑Tue May 11, 2010 5:46 pm
Ok everybody, here is the new video driver, currently in Beta.
It give you the following features:
* Turn on or off alternate frames.
* Have different DFILES for alternate frames.
* Change number of character lines for each alternate frame.
* Add Interrupt routine to top or bottom margin.
Current problems:
* Still uses IM1 in the ROM so system variable D_FILE still used. Fixable.
* Should possibly have a graphic library with sprites, tiles, scrolling, etc that takes into account the alternate frames.
* Should also have some kind of keyboard scanning in VSYNC.
* VSYNC has to be a fixed period of time.
Notes:
* There isn't provision to add an interrupt routine on blank frames. Not sure what would be required but its easy to add your own. A blank frame is just 192 raster lines, similar to top and bottom margin raster lines, e.g. with NMIs.
Screen shots
title.png
Would be very interested in feedback as it stands plus if you think it should have anything else. Also if anyone could try it on a real zx81 and let me know what its like I would appreciate it.
And of course, the £64000 question. Would anyone use it?
Cheers.
Does anyone still have the files for this video driver?
They are no longer available on the forum server
Re: Developing new ZX81 Video Driver
Posted: Wed Jun 03, 2020 6:17 pm
by zx81ultra
Also interested, I hope someone have the files
Re: Developing new ZX81 Video Driver
Posted: Wed Jun 03, 2020 8:50 pm
by msch
I will search old backups of the forums if the files from 2010 and before exist. From 2011 to present, all attachments should be available.
Re: Developing new ZX81 Video Driver
Posted: Thu Jun 04, 2020 12:48 pm
by msch
Sorry, the missing file was not part of the data transfer from the former server.
Re: Developing new ZX81 Video Driver
Posted: Thu Jun 04, 2020 7:02 pm
by 1024MAK
As I understand it, most (if not all) attachments prior to 2011 (approximately) were lost at that time. This was before I joined, so I don’t know any details.
So your best hope is if a member has his/her own copy and can find it, or the original poster still has a copy.
Mark
Re: Developing new ZX81 Video Driver
Posted: Thu Jun 04, 2020 7:17 pm
by msch
Yes - before migrating the forums to my server I made a complete backup from the old system. Before 2011 there are only a few attachments. I will ask Rich - maybe he has an old backup which includes the missing files...