I've been playing Fire Red and I want to try cheats. Specifically, I want to change the gender of the player character. I've tried to figure it out on my own, but I've failed. How would I go about doing this?

It depends on the type of cheat you're trying to use.

If you're trying to use a built-in glitch or bug, then you're kind of on you're own for that, unless you can find more info about how to do it online / from some one here.

If you're trying to use Game Genie or Action Replay (Pro?) codes, then that's simple to do for the most part. You have to press Ctrl + F12 to bring up the cheat menu in Mednafen. From here, it works something like the command line in many different programs (ex: press 1 Action Reply, press 2 for Game Genie, etc, then you press "Enter" to enter the command.

If you follow the steps it gives you, you can name the code, enter the actual "AHKD-DBKB-SVJD" code itself, and many more options. You use Ctrl + F12 to exit the menu, and then press F12 alone to enable or disable all active cheats without needing to enter the menu again.

Just make sure the code entered is for the correct program, since Action Replay codes won't work on the Game Genie option of the cheat menu. If you have any further questions, please let me know I attached a screen shot so you know what to look for.

Image upload: 289x173 totaling 18 KB's.

Mynamescox44 : I don't have all those options. I just have this: 
1) List Cheats
2) Cheat Search...
D) Display Menu

Command>

Hmm. That's odd. I can't remember for sure, but I'm almost positive all those options were there the first time I used it...

It's possible that you might have to go into one of those 3 options listed and enable Action Replay / Game Genie to be used, but I really don't think that's what I did when I first used it. If you can't figure out a solution by searching through those default options, you could always try PMing the RGR Staff Inbox. I'm not really all that proficient with it to be honest, I just try to help where I can.

I'll play around with it myself since I'm in the middle of playing a game any way, and get back to you if I find some thing. Here's the link if you would like to PM the RGR Staff, since that's usually the best way to ensure a response (threads can be more easily missed, though we do try our best).
https://www.vizzed.com/boards/sendprivate.php?userid=35245

After doing a little research, this subject is probably way above my level of expertise. If you want an in depth explanation on how to make it work, I think the answers given in this forum should suffice.

What I mean is the multiple explanations I've found so far make it seem like this is more effort than I'm willing to put in to learn how to make this work. It seems like you have to manually change / alter the code language to get it to properly work in Mednafen because of the way GBA codes are encrypted, but these threads are quite a bit old, so it's also possible they're out of date.

Just a heads up, when they talk about using Alt + C to open the menu, that is our equivalent of using Ctrl + F12, and them using Alt + T to toggle is our equivalent of using F12 to turn them on and off. I'm sorry I couldn't be of more help...

Anyway, here's the link I mentioned:
https://ubuntuforums.org/showthread.php?t=896648

And another just for clarification:
http://forum.fobby.net/index.php?t=msg&goto=893&

Mynamescox44 : I 'll take a look at these forums. Thanks for the help