How do I add "half-resolutions" on ATI drivers?

[TheManuel]

I don't know how else to describe it in the subject but here is what I am looking for:

Most video cards, support low resolutions like 320x240 and 400x300 that get doubled by the video card chip but MAME can draw these resolutions instead of 640x480 and 800x600 for a huge performance benefit on old computers.  The final scan rates sent to the monitor in both cases is the same but the difference is in the performance boost.

I found on the web how to add custom resolutions to ATI drivers by appending them to a key in the registry (NVidia can do it directly from the driver).  But I would like to know if there is a way I can add low resolutions like 384x224 that the video card can then double.

Any input will be appreciated.

[ahofle]

I answered you in the Soft15khz thread:
http://forum.arcadecontrols.com/index.php?topic=66402.msg829288#msg829288

Let us know how it works (I haven't tried any line doubled resolutions yet).

[ahofle]

I thought about this some more.  What card are you using again?  If it's ATI have you tried the latest drivers?  I was having the opposite problem as you (ATI was adding those bogus line doubled resolutions like 320x240, 400x300, etc. and I wanted to get rid of them to add the real ones).  I know on the 9600XT and 9800 Pro they were there.  I had to use a really old Catalyst driver to get rid of them.

[TheManuel]

Coincidentally, I just posted the results of last night's tinkering on the Soft15kHz sticky post.

The card I am using is that Radeon 7500 (from a Dell computer) that I bought from eBay with the latest Catalyst drivers that the ATI website offered for my chipset.

Please check my recent post if you would for more information.

I have worked on this for 4 nights in a row to no avail.  I simply refuse to accept hardware stretch because I notice the difference in the softening of the picture and after seeing the kind of control I was having with my laptop's NVidia drivers I don't want to settle for less.

My other problem is that I need those doubled low resolutions because if I tell MAME to draw at twice the resolution insted, the performance hit on my old MAME computer is enormous.