AVGA -> vertical hold sweet spot

[rampy]

Hi, I'm using a vertically mounted WG19K4675 ( manual PDF) arcade monitor w/AVGA card in DOS using well... dos mame.

I'm having trouble finding a sweet spot where both the lower res games and the presumably higher res games don't "roll".  i.e. if I lock in one steady (say pacman), the other one (say... 19XX ) will scroll and vice versa.  Sorry I haven't made note of which res mame is auto picking...

To give another example, the original POST/bios screen rolls... but the ECSD screen and DOS prompt are stable able.

Here's a previous thread from old ultimarc msg board with similiar issue.  

Andy replied to the thread and said, " Some of the resolutions are 50 Hz and some 60 Hz. It should be possible to find a setting of the vertical hold which locks on all resolutions."

apparently 1spoon still had issues it seems and I wonder if either he or the original poster worked it out, and if so.. how? Also  found a thread on the new ultimarc board by 1spoon but still not sure how it worked out for 'em...

Did those guys eventually find a sweet spot?  Are there monitors that are less forgiving (mines 20 years old!) or parts that could fail that would lessen it's ability to cope with variences in vertical hold or what have you?

Instead of futzing with that vert hold pot endlessly, my other idea was to lock it down for a common resolution... and then use AdvanceMame and ADVV to tweak the resolutions that mame chooses to make the monitor stable/semi-centered/happy =P   That's a bit of a pain but doable... I'd like to try some of the .ini file stuff that garv(?) has figured out using the avgares utilities, BUT that requires loading windows in order to configure it (even if you end up just copying/batch filing in the .ini files to be used by DOS mame... in DOS ... later)  Is there a download of a "good" advancemame.rc or other configs/tweaks/settings?

*shrug*

Thanks!

Rampy

---
I orginally posted this
on the ultimarc board but was hoping to broaden the audience for more input (plus i know that not ever monitor guru here is a regular over there)  --> thanks in advance for any replies/insight (either here or there)

[rampy]

Still have this issue (*bump*)

Are there components on the chasis (i.e. cap kit) that would make an older monitor more sensitive to changes in refresh rate

i.e. going from 50hz, to 53hz, to 60hz?

Using a "real" arcade analogy... if you had a jamma cabinet and swapped between an older game and a new game and couldn't find a vhold sweet spot, what would you do?

*shrug* --- can you tell I hope pac-fan finds this thread =P

Rampy

EDIT: I sometimes can get say 640x480 interlaced and the 60hz modes to play nice... but the next day if I turn on the cabinet --> one or the other will roll and need a micro adjustment on the vhold

[MrSaLTy]

I have never been able to find that 'sweet spot' on my monitor. Its a 20-sumthing
year old electhome gb-07.  I had issues when it was hooked up the the PC straight
and used arcadeos and still do with arcadeVGA.  Certain games that use a slightly
different refresh rate will roll and a microscopic change to the hold will correct it.
But uopn leaving the game and going back to the frontend will result in the roll and
need to be adjusted back again.  I have recapped this monitor also so its not a
function of old caps in the monitor.  These monitors where not designed to run
at changing resolutions and refresh rates ( I mean you can but they need to be adjusted)
and I have resigned myself to just having to live with it, or get a D9200. I have tried to
get it 'right' for 4 years now and its just a no go.

[rampy]

thank you for sharing your experience mr salty... if a cagey veteran such as yourself., has the issue that's reassuring in some damning way =P

HAve you checked out pyronius suggestion regardin using gavin's avga res tool, only displaying 60hz modes, and smoothmame to have it force the vsync of all games to 60hz (which also has the side effect of elimanating tearing in games)

*Shrug*  I guess that's what i'll try next.

I also had the idea of having "parallel" (not in the electrical sense they'd be distinct and isolated from eachother in order to prevent resistance halving) pots for the vhold  that could be switched between (dpdt switch(es)) at different values for different resolutions... but at that point *Shrug*  might as well extend the pots to a more accesible location... or just deal, I guess...

I guess my other question would be (to the board at large): are more modern arcade monitors (say built in the last 10 years as opposed to 20 years ago) more forgiving with the vhold issue?

Thanks again for your thoughts.

Rampy

[kspiff]

I have the same issue with 2 Electrohome GO7s.. the one from my RoadBlasters works fine for RoadBlasters, but the pic rolls horiz/vert (both, in my case) in my Pac-Land.  Supposedly there are small modifications that can be made, but I have yet to find out what.

To answer your question about newer monitors, my current fix is to just bear with playing Pac-Land on a 13" from a more recent Pit Boss gambling machine I keep around for testing.  Worked great, didn't have to adjust it at all!

[tom61]

Using a "real" arcade analogy... if you had a jamma cabinet and swapped between an older game and a new game and couldn't find a vhold sweet spot, what would you do?

I'd adjust it for that game and not bother with it until I changed games.   This is why most Jamma games that have been in a home for awhile tend to have wheels on the bottom.

Anyway, here's something to try, pick up TV Tuner cleaner at Radio Shack or other electronics store and use it to clean the V. Hold POT. There might be dust or other particulates in the POT that are preventing you from physically being able to hit the sweet spot.

[rampy]

tom that's a good point regarding the contact cleaner...

re: the other point.  I just was using that as a "real" arcade example.  in a mame cabinet -> i'll be playing many diffrent games w/different resez's all the time...

Rampy

[OSCAR]

I'm sure it depends on the particular monitor... but in my experience, finding the "sweet spot" is possible.  It took a bit of fiddling around with the v-hold, but I was able to set the v-hold on my W-G 7901 (circa 1988) so that it can now display any game I've tried so far without making any monitor adjustments between games.

In fact, I've become so confident in the capabilities of the ArcadeVGA & CGA arcade monitor combo in my cocktail that I'm going to retire the D9100 in my upright cab and replace it with a W-G 7200 & ArcadeVGA because that looks so much better for arcade games than the D9100 w/ nVidia combo I'm using now.

[tom61]

Oscar, does the D9100 have all the capabilities of it's larger cousin, the D9200? If so, why not try hooking up the ArcadeVGA to that?

[JoeB]

I had the same problem with my 25" WG 7000 series monitor.. horizontal games look great, but others (like pacman) rolled..

I then tried using smoothMAME, and it fixed all my problems!!!  All games work PERFECTLY!   smoothMAME locks all games to 60hz! so you tune the monitor to that (BIOS, POST, DOS, games.. all locked at 60!)

[OSCAR]

Oscar, does the D9100 have all the capabilities of it's larger cousin, the D9200? If so, why not try hooking up the ArcadeVGA to that?

The D9100 is really not that close in comparison to the D9200.  The D9100 is basically an open frame PC monitor with a higher dot pitch.  It doesn't appear to even support 15kHz according to the spec sheet, but I haven't actually tried it.  According to the spec sheet, the horizontal frequency range on the D9100 is 30-70kHz and vertical is 40-160Hz.