What's that screen flashing?


EvilDragon

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I'm just curious about this really excellent emulator... :)

Some games have flashing screens... looks like the original colors change with somewhat wrong colors about 10 times a second... the same time the emulator gets incredibly slow...

Otherwise it works well and fast (without farting sound :lol: )

I'm just curious if anyone (or skeezix :)) has any idea what this flashing could be...
 

golgotha

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if your using a automation/pompey/medway etc pirate groups disc its most likely depacking(decompressing) the flashin is to let you know what its doing, as it takes longer to load than an original version, if your using an original image then im not sure :huh:
 

slainer68

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i have got this problem with Nebulus (original disc)....
the background is flashing and the emu becomes very slow...
 

skeezix

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golgotha has it; the screen flashes when the palette is changing the background colour. The real question is why they do that..

The answer is as golgotha put it, and another reason..

1) The cracked packers flash the screen or even a scanline's colour, to let you know they're unpacking. Its easy to change the background colour (one write to the video system), and then it magicly works.. so low processing hit, effective result.

2) Games; the ST had a limited colour palette.. 16 colours at a tiime, in low res. But coders, being ingeniuous, decided they would honour the 16colours at a tiem thing on a per-scanline basis, or even sometimes oan per-half-scanline basis. So as the game renders a screen, it can change the palette as it goes.

We *render* by scanline, but currently do not have a per-scanline-palette. So if the game changes the palette 50 times as it goes down the screen, you'll get major flicker.

Dungeon Master is typical; it has a top portion of the screen, a bottom portion (both for controls), and a middle gaming portion. Nebulous.. same way I think. The middle gaming region has a custom palette, separate from the other area.s So it uses 3 palettes.. so you get a flicker about every 1/3rd of a second :)

I'm working on that, too :)

jeff
 

r0lf

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EvilDragon posted on May 6 2003 said:
I'm just curious about this really excellent emulator... :)

Some games have flashing screens... looks like the original colors change with somewhat wrong colors about 10 times a second... the same time the emulator gets incredibly slow...

Otherwise it works well and fast (without farting sound :lol: )

I'm just curious if anyone (or skeezix :)) has any idea what this flashing could be...
It might be a hint or a herring, but on turrican the flash starts at about the same time a little message at the bottom of screen popups up (where the keyboard map usually lives).

it looked like a error code of some sort relating to an overrun...

....seriously tho, when this emu works, it rocks! *so impressed*
 
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