The Sony Playstation2 has several options that are all available independently of one another. That is to say, if you want to install a Hard Disk Drive then you do not necessarily need to install a mod chip.
In addition, to play back up games, you also do not need a mod chip.
Here is a breakdown of options available for the PS2.
To play back up games from disc, you need either a
- DMS4 Lite mod chip
- DMS4 Pro mod chip
- Swap Magic software
To play games from a hard disk drive, you need a Hard Disk Drive and either a
- DMS4 Pro mod chip and a Sony Network Adapter
- HD Advance software and a Sony Network Adapter
- USB Extreme software and an external USB Hard Disk Enclosure