[matalog]

Does anyone have an instruction manual, or a link to one, for the NES Pro Action Replay device?

If not, any in-depth descriptions of what it allows, maybe compared to game genie?

[Psyklax]

Why, do you have one? I don't know much about the NES version but I used the SNES version. Being a consumer device, there's a lot of nonsense talked about PAR and GG by people who have no idea how they work. Of course, around here we know such things.

The main difference between the Game Genie and the Pro Action Replay, as far as I'm aware, is that the GG patches the ROM before the NES can see it, whereas the PAR patches the RAM while the system is running.

So to illustrate the difference, imagine you want infinite lives. The GG code will find a specified address in the ROM, perhaps the instruction for decrementing the lives counter, and replace it with something that does nothing, thereby giving you infinite lives. The PAR, on the other hand, will simply find the RAM address where the lives counter is stored, and freeze it.

The advantage of the latter is that you can use it to make your own cheats - I remember doing so on the SNES. Making Game Genie codes requires a good understanding of assembly. However, I somewhat prefer the GG approach, as a hacker, because it can be permanently applied to a ROM file if you so desire, and it just feels right. Also, there are some effects that can't be achieved by merely freezing RAM addresses.

[Jorpho]

I wasn't sure such a device existed at all in physical form for the NES.  Apparently it was an EU exclusive?
https://www.consoledatabase.com/accessories/nes/datelproactionreplay/

[POWCo-op]

I never enjoyed entering the long codes for Game Genie.

[xorxif]

Edit: The device I'm thinking of is the GAME Action Replay, NOT the PRO Action Replay. I never saw the PRO Action Replay for sale anywhere in the USA, nor did I ever see a used one.

As for the GAME Action replay, I saw a brand new one for sale at a Software Etc (anyone remember those?)
Some years later I also acquired a used one, although I think the battery was dying as it became somewhat unstable, and after a while would not work at all.
While it worked, it was a fun novel little device!

[KingMike]

I wasn't sure such a device existed at all in physical form for the NES.  Apparently it was an EU exclusive?
https://www.consoledatabase.com/accessories/nes/datelproactionreplay/

It was definitely not as easily found in the US, if it was released at all (aside from importing from mail-order companies that advertised in magazines).
Possibly because the GG was distributed by a much more well-known company in the US (Galoob), which probably allowed them to talk more stores into selling the device, against Nintendo's wishes.