DOS76 said
If you are using MAMEUI you can have MAMEUI launch the vertical games on your vertical monitor that is what I do. Actually I just reread your post and I am assuming that when you say you change your primary monitor that you have a vertical monitor also that you are changing it to. If not just ignore my inane ramblings. If you do have a secondary vertical monitor just go to the game in MAMEUI and right click on it and choose properties then you can choose which monitor you want to launch even better you can go to Vertical option in the side bar and right click that follow the above steps and all your vertical games will launch on the vertical monitor.
Jason Carr said
Hi @NefariousJoe, the AutoHotkey script does run before launching the game, so you could indeed use that to send a key stroke. @DOS76's suggestions might solve your issues though; I'm not sure.
Thank you for the responses.
First, yes, I have a second (well, third) monitor that I keep in portrait for, partially, this reason. And second, that's excellent news. I never knew what the order of operations was when launching a game. I will slap together an AHK script and see how it goes. Thank you both.