Roadmap for making a test system with a scart RGB tv

[keropi]

Hiya!
since it will be ~2 weeks before I can pickup a mvs cabinet that I found (not to mention waiting some more for a j-pac) I decided to built a temporary test system using a scart RGB trinitron tv so I can experiment a little and see if I get the process correct.
As a test system I have an old P4 pc with 1GB ram and a 4870 vga (this is just a test system , I'll  obviously use something way better in the cabinet - but not the 4870: I'll get a 4350 or use a 5450 once they are supported) running windows XP.

So would something like this work?

1. install CRT Emudriver 1.2b for Windows XP-32
2. get latest GroovyMAME with some horizontal test roms (like snowbros that is 256x224px)
3. make a vga->scart cable as described here: http://www.geocities.ws/podernixie/htpc/cables-en.html , select a 15khz screenmode and connect vga to tv

I have read the documentation on Calamity's website but naturally I have some questions 
a. do I need to use and configure VMM+ArcadeOSD if I use GroovyMAME? is it wrong to assume that these tools are to be used with other mame builds and other emulators?
b. after I create a MAME.INI (with "mame64 -cc" command) do I need to change the monitor type from the default generic_15 one?
c. I remember reading that on a 64bit-capable system MAME64+64bit-OS behaves better than MAME32+32bit-OS , is this still the case?
d. what about centering , will I need to make adjustments from the tv each time I select a game with a different resolution?

I am sure I am missing something so any help/tips/pointing-to-the-right-direction will be greatly appreciated 
Thanks in advance!

[haynor666]

a) not necessary as crt driver has built it many custom modes but to make sure that You have all You need I recommend to generate resolutions with VMMaker

b) recommended as generic_15 does not allow resolutions like 288x240@60,60 (Pacman will work slightly slower because 60,6 Hz will not be allowed for 288x240). Mode arcade_15 has wider range and most of TV (after 2000 I think) will support extended frequencies

c) Right now windows 7 x64 is the best. In theory XP x64 is second but due my performance problems with driver under XP x64 I don't recommend it. XP x32 is the slowest one but still the safest one. Note that Taito Type X will only work correctly on XP system using interlaced resolutions.

d) almost all the time You had to adjust geometry sometimes little, sometimes much. Examples:
256x240@60,6 to 320x240@59,15 - not too much
256x240@60,6 to 384x256@55 - You will have to because bottom part of picture will not be visible

[keropi]

Thanks for the info haynor666 , I changed the monitor type to arcade_15 and ofcourse ran VMM - figured that my self once I finished the driver installation 
Had to use powerstrip to switch XP to 640x480 , display properties did not allow anything lower than 800x600 - even with unchecking the hide unsupported resolutions in the monitor settings.
I think I'll go the win7/x64 route when I build the machine. Tried some games and I see what you mean about centering, almost all low-res ones need centering.

So I am very pleased with the result, scrolling seems butter smooth in the few games that I tried and the image quality is very nice taking into account that I use an old JVC 14" set . The p4 isn't anything special too, a via-based 1.9ghz p4 machine... but enough for testing purposes 

Here is a pic of the tv in action



and the vga->scart cable , just a quick build:



I also tried ArcadeOSD in order to see if centering works (in it's own screen that is, I understand GM won't use these settings unless specified) but messing with Horizontal/Vertical settings did not made an change... maybe it's the tv? Or you can't shift the picture using it?

At any rate, I am pleased even with these basic results  As always any help is appreciated.

[adder]

i wouldnt bother with powerstrip anymore, just use the utility 'quickres' if you need to switch desktop resolutions

https://www.ultimarc.com/quickres.exe

[keropi]

^ thanks for that, it does the job excellent 

[haynor666]

Better use ArcadeOSD to switch 640x480. That's why I wrote previously that most people will have to use ArcadeOSD only once.