According to the files in the archive terminal Ren used to live in following address:
Neo Berlin Residential Area Sector G9, 30010, Block C
This is the low-spoiler guide for "Visit the Old Flat" puzzle in Encodya. Unlike in normal walkthrough, you get gradual hints on how to solve the puzzle. Click the big button below to see your first hint. If the hint contains a spoiler, you will be warned about it before clicking.