Different between Pioneer 420H & 520H?

[maya2000]

Hi I'm new to this forum. I read the whole thread which took me 3 hours or more and it makes a good read.
I need some advice abot Pioneer DVR units.
What is the different between the Pioneer DVR 420H and the 520H?
I've a Pioneer DVR 420H and I want to make it multiregion.
Multiregion:
What software do I need? Can I use the regfree520_720 software or do I need a special version?
Service Remote CGF1381:
I also want to know what file to use with my Palm IIIc & OmniRemote? I've tried the file which was posted in this forum converted it and transfered back into my Palm but I got no reponse from my Pioneer unit. Maybe someone can post a working file for me.
As I told you I am very new to all this. Anyway I thank you in advanced

[Frobozz]

I only can help with your first question. The 520 has a Firewire DV input and the 420 does not.

[maya2000]

Thanks for the info.