And the hero of that story? Not Sony. Not a game developer. It’s a piece of open-source software (7-Zip) and its ruthless, almost artistic love for eliminating redundancy.
At first glance, pairing (a hyper-efficient compression format) with PS1 games (ISO or BIN/CUE files) seems purely practical. But dig deeper, and you’ll find a fascinating collision of 1990s optical media limitations and 2020s hoarding instincts. The Problem: The Plastic Disc’s Bloated Ghost A standard PS1 CD-ROM holds up to 700 MB. But here’s the dirty secret: a huge chunk of that data is padding and error correction codes (ECC). Why? Because in 1994, CD drives were slow, unreliable, and prone to skipping if you bumped the console. Sony filled discs with redundant data to ensure Crash Bandicoot didn’t crash.
So next time you see [name_of_game].7z , know that you’re looking at a digital ghost—a CD-ROM that’s been flayed of its padding, stripped of its plastic, and reduced to pure, playable essence.
Here’s an interesting, slightly geeky deep-dive into the world of . The Alchemy of Compression: Why PS1 Games Live Inside .7z Files In the dark corners of hard drives and the sacred archives of abandonware, a peculiar file extension reigns supreme: .7z . And nestled inside these unassuming zip-like packages? The jewel-encrusted ROMs of PlayStation 1 games.
This isn’t just compression. It’s . The Collector’s Paradox Visit any retro gaming forum, and you’ll see the holy grail: “PS1 Redump Set – 7z compressed” . Redump is a project that creates perfect , 1:1 disc images. A full US PS1 Redump set is about 1.4 TB in raw ISO/BIN format.
Why? Because 7z is brilliant at detecting and eliminating —those giant blocks of zeros or repeated filler data that the PS1 never truly needed. It essentially says: “Oh, you have 300 MB of ‘0x00’ repeated? Let me just write ‘repeat 0x00 300 million times’ in 4 KB.”
Enter (the open-source archiver behind .7z ). Unlike the ancient .zip or even .rar , 7z uses a LZMA (Lempel-Ziv-Markov chain algorithm) — a brain-meltingly smart compression method that doesn’t see files as files, but as streams of repeating patterns . The Magic Trick: Where 7z Shines Here’s where it gets interesting. When you compress a PS1 .bin with standard ZIP, you might save 10-15%. Meh.