XPC-4 Questions (24khz -> 31khz)

[Esquire]

I have a PVM 20L5 that I use for my X68000 and various early computers (MSX, Amiga, Atari ST, etc). I'm looking to integrate an FM Towns into this setup, but I need a way to handle the prevalent 24KHz video output. Unfortunately, line doubling to 768p will not work. While the 20L5 will sync with this out of spec signal, it also locks the aspect ratio to 16:9. I believe this is because it considers it to be in the 720p range.

So I'm turning my attention to the XPC-4. I've seen it touted as the ideal solution for scaling Japanese computer signals, but the intended usage is with a VGA monitors that have full sync. So I need some help with this unusual use case. Here are my questions:

• Can the XPC-4 upscale 24khz / 384p to 31khz / 480p?
  • If so, what does that look like? Non-integer scaling or 384p in a 480p frame?
  • How does this compare with the 31khz scaling that the FM Towns FS does?
• Can the XPC-4 pass through 15khz and 31khz while only upscaling 24khz?

I'd appreciate any help you can provide. And before anyone points out the obvious, of course I could just look for a trisync monitor, but what's the fun in that?

[thchardcore]

Bump. Would like to know as well.

[incrediblehark]

Hey! Been playing around with this and wanted to give you some quick answers. The xpc-4 can scale 24khz to 640x480, you may need to make some adjustments in the xpc-4 to get your image just right, but the auto adjust works well to start.

You can also pass through 15/31khz. Use the hd15/vga out on the xpc-4 and set the output on the device to anything but rgb, you will still get the osd and adjustments from the xpc4 but it won’t convert the signal at all. Just switch output to rgb when running 24khz and you’re good to go! No need for any signal splitters etc. it’s actually pretty convenient.