Re: Static PET video timing?

From: afachat_at_gmx.de
Date: Thu, 30 Mar 2023 23:37:49 +0200
Message-ID: <8408433.T7Z3S40VBb_at_euler>
On Mittwoch, 29. März 2023 22:28:41 CEST Rhialto wrote:
> On Wed 29 Mar 2023 at 21:02:26 +0200, Torsten Kracke wrote:
> > Apart from what Olaf was writing there is also the demo "A Bright Shining
> > Star" for CRTC-less PETs which for it's PECBM-mode uses the same technique
> > as in the HI-RES program to provide pseudo hi-res graphics of 10 chars
> > width by updating the video-RAM on the fly:
> > 
> > https://www.pouet.net/prod.php?which=91735
> 
> Because of this demo I added a compile-time option to VICE (r43618) that
> allows you to delay the vertical blank interrupt a bit. For this demo,
> 16 seems to work well: when running the "real iron, non emulator"
> version, the starshine at the end looks ok, or at least it doesn't have
> the extra horizontal lines to its left that it had before.
> 
> The option is by default off because it adds overhead that is totally
> unneeded in 99,9999% of the cases.

It's amazing what people now do with the PET. I admit I was playing with 
writing a demo or simple game to show off CRTC manipulation during "rasterline 
interrupt" myself, but I would have never been able to pull off what they did.
In a way I did it before it became popular recently, but only as PoC and not 
as real demo...: http://www.6502.org/users/andre/hwinfo/crtc/pet/index.html

btw, here's the result of my (and other people's) analysis of the static PET 
timing:
https://forum.vcfed.org/index.php?threads/commodore-static-pet-early-dynamic-pet-video-timings.1242511/

André
Received on 2023-03-31 00:00:03

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