Hey HowDoUPlay - I really appreciate you looking into this man! I put together a quick video of the 3 cartridges I'm using and what I'm seeing - The honest answer is that I don't know which versions I have, but I can't press down to get the backwards jump, and I can't do the TCRF menu-cycling thing on any:

Here are the interesting timecodes:

2:53 - Example of no ability to backwards jump while holding down
3:32 - Example of stage 3 trick on Famicom cartridge (text only label)
4:14 - Example of holding select on menu (no cycling per TCRF)
7:32 - Example of stage 3 trick on Famicom cartridge (cartroon label)
10:43 - Example of stage 3 trick on NES cartridge (5-screw)

It may be that there are more than 2 versions, it may be that I'm not doing the backwards jump trick correctly... I have no idea! But I 100% cannot get the backwards jump by holding down, and my understanding is that THAT'S the main reason to use PRG0. Appreciate you looking into this either way - just followed you on Twitch, looking forward to watching you stream

The stage 3 glitch is possible on PRG1 as Lojen states in this thread: https://www.speedrun.com/dkjr/thread/bxint

The big advantage with PRG0, so far as I know, is that you can just hold down to get a backwards jump in PRG0. The trick is very difficult and inconsistent to pull off in PRG1 because you have to perform a standing backwards jump and quickly switch to holding down before grabbing the vine (my video on the leaderboard takes 3 tries to do the trick because of this.)

You can also get a pixel perfect forward-facing jump to pull this off on PRG1, but this is also very inconsistent, see this submission from Japisman:
https://www.speedrun.com/dkjr/run/zp8dnv8y

I was able to find some documentation on other differences between the versions/revisions as well, such as differences in color on the fruit: https://tcrf.net/Donkey_Kong_Jr._(NES)

Thanks for the quick response! Both my famicom cartridges are dated 1982, so the mystery continues...

Is there any way to determine the version (PRG0 or PRG1) of the NES/Famicom DK JR cartridge from the packaging, labelling, number of screws, etc.? I own three versions of the cartridge and none seem to be the PRG0 version:

- 5-screw NES cartridge
- Famicom cartridge with the cartoon label
- Famicom cartridge with the text label

I'm only aware of two other versions of the cartridge:

- Donkey Kong Classics
- 3-screw NES cartridge

There's surprisingly little documentation about the PRG0 version online, and I haven't been able to find anyone selling one. Is it just incredibly rare?