Reliving VIC20

[chysn]

I am assuming that as nobody has reported any issues, that my test program runs ok on an NTSC machine.

Ooh, sorry, I missed this. Yes, works great on my real NTSC machine!

As for video detection, I actively avoid situations where I'd have to care about the video system in use. But I feel like I'd probably approach it by offering two versions of my program and letting the humans sort it out.

I recently bought a copy of Astro Nell on cassette, and it doesn't work on my NTSC machine. That it's made for PAL is just not something that they cared to mention. So, I'd say, thinking about it at all is a considerate move.

[Mike]

I recently bought a copy of Astro Nell on cassette, and it doesn't work on my NTSC machine.

There exists an NTSC version of Astro Nell, which you can download at 4mat.itch.io.

I'd probably approach it by offering two versions of my program and letting the humans sort it out.

That's somewhat okay for downloadable stuff, but it's rather cumbersome to have two cartridge versions. People just tend to miss such details when ordering things, and then a costly exchange is necessary to sort this out.

[chysn]

There exists an NTSC version of Astro Nell, which you can download at 4mat.itch.io.

Thanks! Perhaps I'll tape over my PAL version on one side!

I'd probably approach it by offering two versions of my program and letting the humans sort it out.

That's somewhat okay for downloadable stuff, but it's rather cumbersome to have two cartridge versions. People just tend to miss such details when ordering things, and then a costly exchange is necessary to sort this out.

Yeah, that's true. A cartridge should have plenty of room for detection, and handling the results of detection. But I'm mostly working in unexpanded, where supporting both systems could make memory tight.

Anyway... I think worrying about other ROMs that people could potentially drop into a VIC-20 will drive you nuts. Check the init table and don't look back. Unless you're writing VIC-20 software that scans MRI data for cancer, everyone will live.

[thegg]

Chysn
Thanks for confirming my program works on a real NTSC machine. Appreciated.

As for checking the video type, I can see that inspecting the initialisation list is as good as any and more reliable than most way to go. So that is what I will do when the need arrises.

Mike
Thanks for taking the time to point me in the right direction in such great detail. It has been an enlightening discussion.

Dave