This cheat for unlimited DP will work at any location with a Holochip. They have varying amount of DP, but if you do this one on the very first stage (File R-01), then you get a large holocship worth 5,000 DP each time.

Anyway, grab the Holochip and then enter the customization menu.

Then quit the customization menu and go back to your game. You'll be at the start of your last checkpoint, and can then go and grab the same Holochip.

Rinse and repeat for unlimited DP and therefore upgrades!!