Can the NTSC VIC-20 show a 22x27 size screen on a CRT TV?

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Ghislain
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Can the NTSC VIC-20 show a 22x27 size screen on a CRT TV?

Post by Ghislain »

With the following code, I'm able to display the entirety of a 22x27 screen size on my flat panel LCD TV:

Code: Select all

10 poke 36867,54
20 poke 36865,18
However, since I no longer have a CRT television, I'm wondering if any NTSC CRT users out there are able to test the above code to me and let me know if they can still see the border (however slight it is) at the top and bottom of the screen?

I am planning to do a VIC-20 project that would require a bigger screen display.
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Mike
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Re: Can the NTSC VIC-20 show a 22x27 size screen on a CRT TV

Post by Mike »

In another thread, darkatx and I got to 23x26 without any cropped borders - on his CRT. Later, freshlamb tried out the NTSC VFLI mode with that exact set of parameters on another CRT and the picture was already clipped at the top.

If you take a look at darkatx's picture, 22x27 should work out, but you also should in any case provide the user with a means to adjust the position of the visible window.
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Ghislain
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Re: Can the NTSC VIC-20 show a 22x27 size screen on a CRT TV

Post by Ghislain »

Mike wrote:In another thread, darkatx and I got to 23x26 without any cropped borders - on his CRT. Later, freshlamb tried out the NTSC VFLI mode with that exact set of parameters on another CRT and the picture was already clipped at the top.

If you take a look at darkatx's picture, 22x27 should work out, but you also should in any case provide the user with a means to adjust the position of the visible window.
Thanks. Looks like 22x27 would be cutting it close, but 22x26 would be a safe option. I'll use the KERNAL print routines to write text to the first 23 rows, while directly storing the character values in the bottom 3 rows in screen RAM to display text/graphics there.
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darkatx
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Re: Can the NTSC VIC-20 show a 22x27 size screen on a CRT TV

Post by darkatx »

I cry when I look at the spare Vic that used to be my cousins...its a goner - pretty much every chip is gone :(

I can only use it for some parts here and there for my working one now.

Can't wait to see what you got cooking Ghislain :)
Learning all the time... :)
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Mike
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Re: Can the NTSC VIC-20 show a 22x27 size screen on a CRT TV

Post by Mike »

Ghislain wrote:Thanks. Looks like 22x27 would be cutting it close, but 22x26 would be a safe option. I'll use the KERNAL print routines to write text to the first 23 rows, while directly storing the character values in the bottom 3 rows in screen RAM to display text/graphics there.
Printing to screen without kernal ;)
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darkatx
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Re: Can the NTSC VIC-20 show a 22x27 size screen on a CRT TV

Post by darkatx »

If you're going to use expansion then maybe you can go with a custom character set for a set screen area/window which would be similar to what Mike and Kweepa use?
Sounds like you need a bit extra room for text and 22 columns might not be enough.
Learning all the time... :)
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