Cave SH3 board - anyone seen this glitch?

[system11]

Hopefully it's not just mine, but hey - it might be...

Mushihimesama, on two monitors (identical types, one is bigger), I get a scanline on the left that is only half drawn. Adjusting the vsync makes this line go about 80% of the way, then the screen can't sync anymore. Adjusting it the other way eliminates the line. On a more modern screen, the line is there regardless of sync settings, perfectly drawn.

Now - the line SHOULD be there, it's got some of the graphics in Not too concerned, as the screen in the Touhoucab is actually the same as in a lot of Candy cabs, and that has no problem at all.

Anyone else seen this? Smells like something that's right on the edges of tolerance for a low res signal.

[Dave_K.]

My Storm Blade PCB has this same problem if the vsync isn't adjusted correctly. This was on a Windy2 tri-res monitor. I don't remember if it had the problem on the regular Windy Nano monitor. I think I ended up just adjusting the width so it wasn't noticable.

[GaijinPunch]

In my experience, Mushi (as well as both Galudas) have such massive resolution, most monitors aren't going to show everything. I lose a good 5 or 6 pixels on the left side of my current monitor. Not sure if that means they'd allow for strange funk to occur on the borders, but worth mentioning maybe.

[system11]

I forgot about that, that might well be what it is - my two old Hantarexes not being able to manage the full resolution, while the Wei-Ya can. Looks like this:

Code: Select all

################
################
################
################
|###############
 ###############
 ###############
 ###############
(obviously not to scale)

Where the | is moving rapidly up and down, there are real graphics that should be in the line, as I say the line gets longer or shorter when I adjust the sync. MushihimeTama doesn't do it, perhaps that one is a lower res?

[thegreathopper]

When I have Mushi in my cab I have never noticed any odd things on the side, I always adjust the screen on my Impress to fit the picture perfectly without cutting any of the side off.

[system11]

Problem solved. I don't know if it's down to the PCB running a higher resolution or not (it would seem like a logical leap of faith), but some screens just can't cope with the full draw area of these boards, hence the flickering longer/shorter far left scanline. However, the game doesn't actually use all the space in the generated picture - I noticed when turning the brightness up there was a whole load of active screen with nothing in it, on the right:

Code: Select all

##########....
##########....
##########....
##########....
##########....
|#########....
,#########....
,#########....
,#########....
,#########....
,#########....
,#########....
(# = pixels, . = unused scanline
, = dead areas of far left scanline, | = flickering part of far left scanline)

I also noticed the screen during bootup, moved to the left by about 15-20 pixels. It's a fairly recent invention, but some games now have position adjustment in test mode. Mushi does. Mine was set to '00' (it's hex) which I believe is the default. Greater numbers move the image to the left (up the scanlines), smaller numbers (wrap to FF and down) to the right (down the scanlines).

So, I moved it to the right a bit, end result:

Code: Select all

..##########..
..##########..
..##########..
..##########..
..##########..
,.##########..
,.##########..
,.##########..
,.##########..
,.##########..
,.##########..
,.##########..
(# = pixels, . = empty scanlines, , = probably half dead scanline area, now unused)

So, there you go - some screens can't cope with higher than usual resolution, and if you try to draw too many scanlines, the screen is unable to complete the full picture within the sync interval. I think that's what's happening anyway. I guess that's why they put in the position adjust (cross hatch option in test menu).