I emailed Chris (I think) about the error I am getting when trying to run DOScab on an arcade monitor. It should be able to use 320x240 mode, which I have set up with the VGA to arcade TSR, but instead is saying mode not supported. I have compiled software myself using Allegro and DJGPP that will display 320x240 on the arcade monitor, so I don't know what could be different in DOScab.
I responded via E-Mail, but I'll copy that response here so everyone can enjoy...
Which TSR are you using? With AdvanceVBE, you should be able to hit 320x240. If that doesn't work, try 512x240. 320x200 will also almost certainly work, but you'll have trouble making anything look good at this resolution. You'll also want to make sure you're skin is set to low-res.skn or low-res2.skn.
(Edit: I see below you have your own skin...)It's possible your hardware only supports 320x240 with an 8-bit color depth; the jukebox requires at least 15-bit color depth. It'll try your requested resolution at 15, 16, 24, and 32 bit color depth before giving up and throwing that error message.
If you can't get it to work, please let me know which video chipset you're running.
I made a nice 320x240 skin too but can't use it
Are you willing to share?
--Chris