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MRT
Account closed
Registered: Sep 2005
Posts: 149 |
FLI Bug
I came across the following situation:
Set the VIC to character mode and multicolor.
Now generate a badline every rasterline and changing $d018 so that the VIC fetches data from a new screen (Video Matrix Base Address) every rasterline...
In this situation the FLI bug only completely appears when the last eight bytes of the charset (the last char in the charset) are filled with $ff.
So, when you fill those bytes with $00, you won't see the FLI bug and the background color is shown.
And no need to mask the bug with sprites anymore!
Even if you draw a smiley in the last char, the FLI bug shows only those smileys!
Now, my questions...
1. Are my findings correct? Or is there more to it?
2. (How) Can this be done in bitmap mode?
I've only tested this on Vice and CCS, it may differ on a real C64 |
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Graham
Account closed
Registered: Dec 2002
Posts: 990 |
Quote: fli bug = vic reads #$ff from screen ram.
And "next opcode" from color RAM. |
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Monte Carlos
Registered: Jun 2004
Posts: 359 |
It sounds, that your starting your fli one line too late.
Check, if you really can do 200 lines fli and not only 198 or 199. You can see it, if theres no fli switches in the last 3 lines or so.
Did you open the borders for fliing ?
Monte
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MRT
Account closed
Registered: Sep 2005
Posts: 149 |
Nope, no open borders...
And yes, I'm doing 200 lines
:-S
And I'm starting fli on line $33, but even before $33 I update $d018 with the right value... |
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WVL
Registered: Mar 2002
Posts: 902 |
Quote: Nope, no open borders...
And yes, I'm doing 200 lines
:-S
And I'm starting fli on line $33, but even before $33 I update $d018 with the right value...
You can't do 200 lines if you're starting at rasterline $33.. you have to open the borders and start at line $30 if you want to have 200 lines...
This is because badlines are limited to $30-$f7.. |
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MRT
Account closed
Registered: Sep 2005
Posts: 149 |
Sorry... must be stoned again... ;-)
Yes Monte Carlos & WVL...
You're both right. Thanx. I was starting one line too late. Curious though, because I was starting on line $33 when the bug appeared, but now I'm starting on $32 and the bug is gone. BUT, the amount of lines displayed seem to be the same as before... 8-S
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Viktor
Account closed
Registered: Apr 2002
Posts: 78 |
Have somebody ever tried the fli and the multi char mode together?
Will it cause something interesting? A new format or something another? |
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Jetboy
Registered: Jul 2006
Posts: 337 |
It's there since forever - "DisplayList" like effects are done like that.
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Oswald
Registered: Apr 2002
Posts: 5094 |
displaylist like effects are not using fli, instead they stretch the very same line forever and change d018 each line to display different gfx.
fli and multi chars together wont really give you anything that couldnt be done easyer using another trick. (see above) |
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Viktor
Account closed
Registered: Apr 2002
Posts: 78 |
Thanks Oswald.
Viktor |
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Jetboy
Registered: Jul 2006
Posts: 337 |
Quote: displaylist like effects are not using fli, instead they stretch the very same line forever and change d018 each line to display different gfx.
fli and multi chars together wont really give you anything that couldnt be done easyer using another trick. (see above)
But that's almost exactly the same as FLI.
First charline in fli is stretched, while bitmap stays unstretched, and changed every line.
In Displaylist-like effects, first char line is stretched and changed every line.
It's not that big difference I would say. Only small difference in cycling.
BTW. how to get rid of the garbage after displaying fli, when you have border color other than black? |
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