Driving a 15 Khz monitor with an ATI card?

[Dave Wave]

I have a 15 Khz monitor in a cab. I have a XP computer that used to drive an AGP Arcade VGA.

The Arcade VGA died, but I have an ATI X1300 I would like to repurpose to take its place.

I would like to use something like CRT Emudriver or Atom 15 or something similar to drive it.

I am a little unclear on which one would be best, considering I have a 15 khz monitor and don't want to fry it when it the computer starts (bios screen) etc...


There seems to be a converter board on ebay that seems to offer VGA to CGA (15 Khz). Anybody tried one? I could run the output of the ATI to the board, the board could drive my 15 Khz monitor.

https://www.ebay.com/itm/Arcade-VGA-to-RGBS-CGA-AV-S-Video-Converter-High-to-Low-Solution-Board-Multicode/183181246685?hash=item2aa67400dd

Any thoughts or pointers?

Thanks,

-Dave

[adder]

hi, avoid the cheap converter boards on ebay they have problems with lag and incapable of coping with different resolutions and refresh rates

i would recommend reading up as much as possible over at this site:
http://geedorah.com/eiusdemmodi/forum/index.php

and also i recommend using the groovymame support forum for further help:
http://forum.arcadecontrols.com/index.php/board,52.0.html

[Paradroid]

I could run the output of the ATI to the board, the board could drive my 15 Khz monitor.

You won't need any converter board: the whole point of the CRT Emudriver is that it will output 15 kHz without any additional hardware. You card will be outputting CGA directly (not VGA) once setup.

If you're driving an arcade monitor, you will need an video amp though.

[Zebidee]

If you're driving an arcade monitor, you will need an video amp though.

Dave must have one or a JPAC already for the AVGA -> arcade

CRT_emudriver is in many ways better than AVGA anyway. You can just take the modes it gives you, or tweak it as much as you want.

You might have to modify your old frontends like mamewah, as they want specific resolutions for layouts. If the mode (& colour depth!) it expects doesn't exist, it won't work. For example, I used 321x240@60 with avga/mamewah and i found it difficult to generate the exact same modes with CRTEMU. So I had to edit all my old mamewah layouts to "re-size" them to a similar & valid CRTEMU mode eg 320x244@60 instead.

Also recommend you go "all in" and get Groovymame going too as it all works well together. I've got it mostly sorted for my XP64 machines now. Some retro-fitting was required (pun intended!).

[Paradroid]

I used 321x240@60 with avga/mamewah and i found it difficult to generate the exact same modes with CRTEMU.

Surely 321 × 240 that was just a dummy label for 320 × 240 (to distinguish from a system mode)? My understanding is that Windows will only accept modes with horizontal resolutions with multiples of 8 pixels.

It's easy to add 320 × 240 using CRT Emudriver and VMMaker: you just add it to your list of resolutions and click generate. VMMaker does all the hard work for you.

[Zebidee]

I used 321x240@60 with avga/mamewah and i found it difficult to generate the exact same modes with CRTEMU.

Surely 321 × 240 that was just a dummy label for 320 × 240 (to distinguish from a system mode)? My understanding is that Windows will only accept modes with horizontal resolutions with multiples of 8 pixels.

Yes, that is mostly true. It is just that in Mamewah chooses video mode according to the background image size you specify in the layout designer. So when porting my AVGA Mamewah setup to groovymame, I had to edit layouts to specify a valid a valid video mode (ie background image dimensions).

It's easy to add 320 × 240 using CRT Emudriver and VMMaker: you just add it to your list of resolutions and click generate. VMMaker does all the hard work for you.

It *was* hard work. I found it hard/impossible to create exactly 321x240@60 with VMM. I'd specify the mode to add, but it kept rounding me to 328x240 or 320x244 or similar. Sometimes at the wrong refresh rate too. After many attempts I eventually I gave up and edited my layouts to match the CRTEMU/VMM modes available.