Author
| Strange video effect in MrGhost
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cax
msx professional
Posts: 1011 |  Posted: May 11 2004, 14:09 |
Will check on openMSX.
Can blueMSX or NLMSX emulate the mentioned effects ?
Any other emulators to try ?
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BiFi
msx guru
Posts: 3142 | Posted: May 11 2004, 14:10 |
Quote:
| >> BiFi: to make things clear, I am going to play MrGhost in an emulator and save it's state exactly before the mentioned effect. Which emulator(s) do you suggest to try this on ?
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openMSX correctly emulates this trick.
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Yeah, but currently lacks a save state. |
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[D-Tail]
msx guru
Posts: 2994 | Posted: May 11 2004, 14:17 |
NLMSX doesn't emulate the mentioned effect (yet). Too bad, while other emulator developers are working on their product, it's quite quiet at NLMSX... Time's standing still, perhaps. NLMSX doesn't even emulate Sonyc correctly (blueMSX does nicely!)...
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GuyveR800
msx guru
Posts: 3048 | Posted: May 11 2004, 14:20 |
Quote:
| wolf_, about that BASIC sine you mentioned, you can achieve it with
10 VDP(10)=VDP(10) XOR 1: GOTO 10
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Interesting, I didn't know that.
Quote:
| Dunno what that DC-bit has gotta do with the sine effect, but the effect's very striking indeed.
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IIRC this bit has to do with the digitization capabilities of the VDP. It's probable the switching of the clock introduces a sine distortion on the sync signal.
Quote:
| Too bad, while other emulator developers are working on their product, it's quite quiet at NLMSX...
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I've been told a new NLMSX release is near. |
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[D-Tail]
msx guru
Posts: 2994 | Posted: May 11 2004, 15:15 |
Quote:
| wolf_, about that BASIC sine you mentioned, you can achieve it with
10 VDP(10)=VDP(10) XOR 1: GOTO 10
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Ah! My bad! Don't try this, on my 8245 it tried to ruin my CRT! Use VDP(0) instead 
So that makes:
10 VDP(0)=VDP(0) XOR 1: GOTO 10
According to the tech manual, bit 0 of R#0 is unused! It initial value is 0, and shouldn't be changed. But if you do, and you do it fast enough, it becomes that sine routine...  |
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[D-Tail]
msx guru
Posts: 2994 | Posted: May 11 2004, 15:19 |
It works nice on both the NMS8245 and the FS-A1ST Jolly good phun!
And try to bash down some keys then. It becomes even more phun! But actually, I don't think this trick is of interesting political value  ... |
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MagMar
msx friend
Posts: 7 | Posted: May 11 2004, 15:36 |
if you start eating chips right now you can see the same effect on the screen you're looking at right now (well maybe not the tft-screens).
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cax
msx professional
Posts: 1011 | Posted: May 11 2004, 16:36 |
Just created savestate for blueMSX 1.4.0 that shows the mentioned wavy effect (yes, it works in blueMSX), but I can't reopen it in blueMSX 1.4.1, is it ok ?
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GuyveR800
msx guru
Posts: 3048 | Posted: May 11 2004, 16:38 |
Quote:
| Ah! My bad! Don't try this, on my 8245 it tried to ruin my CRT! Use VDP(0) instead
So that makes:
10 VDP(0)=VDP(0) XOR 1: GOTO 10
According to the tech manual, bit 0 of R#0 is unused! It initial value is 0, and shouldn't be changed. But if you do, and you do it fast enough, it becomes that sine routine...
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Even weirder!
That bit is idd unused, and wasn't used in the MSX1 VDP (TMS9918) either.
I wonder what actually happens!? :/ |
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mars2000you
msx master
Posts: 1723 | Posted: May 11 2004, 17:00 |
Quote:
| Just created savestate for blueMSX 1.4.0 that shows the mentioned wavy effect (yes, it works in blueMSX), but I can't reopen it in blueMSX 1.4.1, is it ok ?
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In version 1.4.0, the joystick/mouse configs were not saved in the save states.
In version 1.4.1, the save states are more complete and include joystick/mouse configs.
That explains your problem. So, you must create a new save state in version 1.4.1 |
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cax
msx professional
Posts: 1011 | Posted: May 11 2004, 17:40 |
Ok, for those who want to see the effect with their own eyes,
here are the screenshots from 2nd level in Mr.Ghost
and savestate for blueMSX 1.4.0 (sorry, have no time to replay the game on 1.4.1):
cax.nm.ru/msx/other/mrghost-effect.html
(hint: move right to enter the unhidden passage, and see the effect the first time. After 15-20 sec, the time of being in the hidden room is over, you will see the effect again)
As you can see, not the whole screen is waving - only about 2/3 of lines in the center of it.
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BiFi
msx guru
Posts: 3142 | Posted: May 11 2004, 18:05 |
There's a 'bonus' stage like that in the first stage as well. In this screen...
not open yet and open |
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cax
msx professional
Posts: 1011 | Posted: May 11 2004, 18:27 |
I'm trying to run mrghost in openMSX windows 0.3.4 by running openMSX.exe mrghost.rom, I hear sound, but the video is corrupted - does it mean C-BIOS is not enough, or I have to specify the type of ROM, or anything else ?
Update: already found it in openMSX manual, sorry for asking before reading.
Now I'm trying again
Update: mrghost just doesn't run with c-bios, or without basic - go figure.
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Arjan
msx addict
Posts: 454 | Posted: May 11 2004, 18:27 |
try:
10 VDP(10)=vdp(10)xor8
20 VDP(10)=vdp(10)xor16:goto 20
or
10 VDP(9)=VDP(9)XOR16:GOTO10
or
10 vdp(0)=vdp(0)xor1:goto10
for some nice effects results maybe depend on MSX model used though... |
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cax
msx professional
Posts: 1011 | Posted: May 11 2004, 19:01 |
Well, with the help of BiFi (hidden stage in level 1 is really easy to reach, just go right 7 or 8 screens), I was able to see the same effect in openMSX too.
It looks a little different from the one in blueMSX.
It starts with waving the same 2/3 part of lines in the center of the screen, and then, after about second, waving propagates to the rest of lines till the bottom of the screen.
I really don't remember how this was on a real machine, therefore I can't decide which of the two emulators mentioned does it better :-)
Nevermind, I don't ask to fix anything, I am already happy with the fact that the effect is reproduceable.
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