Hey Moltex here's a step by step, hopefully it's clear enough.
You need to be watching two RAM values to get this trick working reliably. 7E007B, which is Mario's speed, and 7E13E4, which is Mario's P-meter. When the P-meter reaches a high enough value, Mario can begin to run at his highest speed, and you need to keep the P-meter's value high enough, otherwise he'll begin to slow down. You watch RAM values by going to the Cheat menu, then "Search for new cheats". Here you find these two values in the huge list, and hit "Watch" for each of them, which should put their value on the screen every frame once you close down the Search for new cheats window.
Ok so now you're watching the values so you can check and see if you mess the trick up, which is quite easy to do. Now you need to be using frame advance of course, I'm assuming you know about that and can use it etc. Once Mario's P-meter is high enough (108 showing on the screen, unless your version of snes9x differs from mine), he can start running at top speed. What you want to do is jump, then release -> on the first frame where Mario's speed is 49 (it will oscillate between 49-48-47-48-47-etc every 5 frames). Note that the value you "watch" on the screen lags behind 2 frames, so make sure to let go of -> so the value STOPS at 49, that'll be Mario's speed.
Now you could just not press -> again and hop through the level at top speed, if the level layout allowed. Doing 6/5 is quite a bit trickier unfortunately. Basically once you have "regular" hopping at 49 set up, you want to NOT press -> for 6 frames, then press -> for 5 frames, then NOT press it for 6 frames, then press it for 5, etc. You need to hold -> for 5 frames to keep the P-meter from going too low, and pressing it for 5 frames will allow it to recharge while still keeping top speed (49) afterwards. To complicate matters further, you sometimes need to time your jumps differently (higher or lower jumps), because when you land you must be in the "recharge phase" of the trick. I don't think I can explain that well enough, so just experiment away and see when during this cycle you should be landing/jumping without losing speed (remember Mario's speed should be 49-49-49-49-49-49 (when not holding ->) -49-48-47-48-47 (when holding ->) and repeat). I suggest checking out an smv where the 6/5 trick is done and with some practice you should get the idea pretty quickly.
Ok this probably wasn't a great explanation. Ask away about the parts you didn't get and I'll try to clarify. You can see 6/5 being done in the 11 exit Super Mario World speedrun in the first room of castle #1, or in the 96 exit SMW run in Valley of Bowser 1, or in the 85 exit small SMW run in like 40 levels, if you need somewhere to study it. Really I think if you get the tools set up properly (memory watch), check out how others have done it, and play around and try stuff for a bit, I think you'll figure it out. It's not exactly rocket science.
Good luck.
