Posted: 9/19/2020 3:38 AM
Post subject: Ram Search: How to Use "Copy Value to Previous"?
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CoolHandMike
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Editor, Judge, Experienced player (896)
Joined: 3/9/2019
Posts: 699
First edition TAS of 2023 Sega TAS of 2023
1) If you open up Ram Search. Click "Search" -> Copy Value to Previous. There is also a button next to the "New" button. 2) Not sure if it is related but there is a Options -> Define Previous Value. What are these and how do I use them? Thanks.
discord: CoolHandMike#0352
Posted: 9/19/2020 4:15 AM
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Dacicus
Editor, Player (69)
Joined: 6/22/2005
Posts: 1050
I don't have concrete examples about when to use them, since I generally stick to the default options. Here's a basic explanation about what they do, though (sorry if it's obvious): 1. This option copies the current value in the "Value" column to the "Previous" column for the addresses in the search. I imagine it would be useful to manually update the "Previous" column at times when the next option might not update it otherwise. 2. This option determines when the value in the "Previous" column is updated. "Last Search" updates it when you press the Search button. "Previous Frame" updates it every frame to the value that the address had in the previous frame. "Original" keeps it at the same value as when you started/restarted the search by pressing "New." "Last Change" sets it to the value that the address had when it changed last.
Current Projects: TAS: Wizards & Warriors III.
Posted: 9/19/2020 4:37 AM
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CoolHandMike
He/Him
Editor, Judge, Experienced player (896)
Joined: 3/9/2019
Posts: 699
First edition TAS of 2023 Sega TAS of 2023
Thanks Dacicus! Now to mess with this a bit more.
discord: CoolHandMike#0352
Posted: 9/19/2020 5:17 AM
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Dacicus
Editor, Player (69)
Joined: 6/22/2005
Posts: 1050
Here's an example I thought up. Say you want to find a counter/timer. You make some assumptions:
  • The value changes every frame.
  • It consistently increases.
You can start a new search, set Define Previous Value to Previous Frame, set Compare To / By to Previous Value, set Comparison Operator to Greater Than, and toggle the Automatically search every frame option. Then you just repeatedly frame advance or unpause the emulator to quickly (hopefully) reduce the options. One potential limitation to this method is that you may not know the starting value and when it resets, but it could save some clicks and time. Other things that you might be able to find using this method include camera position addresses and RNG addresses. You do have to make some correct guesses/assumptions about how the game behaves, though.
Current Projects: TAS: Wizards & Warriors III.