2. Retro gaming console
The most obvious options are a retro gaming machine, running a dedicated game server or use Steam streaming.
It’s also worth noting that even an old PC can be used to play classic games. GOG.com is a great place to start, with a huge range of old favourites for sale.
To play really old titles, or those from different systems, you need an emulator program.
RetroArch is one of the best and will even run on other hardware, such as an old tablet. Getting set up is not super easy (and needs separate emulator cores), but there is a large community and plenty of support to get you started.
For a simpler approach, Lakka is a custom Linux distribution based on RetroArch that makes the whole process much more user friendly.
Installed like an OS, it turns your PC into a retro gaming console, with a neat GUI. It also has emulator cores pre-installed, and is optimised to use a gaming controller.
The other side of retro gaming is finding the game ROMs to play. Many are protected by copyright, but can be found on torrent sites. There are also lots of public domain and legal ROMs — a good place to start is www.pdroms.de.
Based on Linux, this free software from Valve lets you build a Steam box, for console-style PC gaming. It can be installed as the only OS or dual-booted and is quick and easy to set up.
The OS includes the Steam client and access to a large library of compatible games. There are heaps of older or low-end titles available that can run on slower hardware.
However, Steam OS is probably best used on your old gaming machine, rather than on a lesser PC. A 64-bit AMD or Intel CPU, 4GB of RAM and a discrete graphics is the minimum spec.
Steam in-home streaming
Rather than trying to run high-end games, your old computer can be used as an interface to your newer gaming rig. This gives a lot of flexibility, such as gaming on a laptop in bed, or using a wireless controller in front of the TV.
Steam streaming also allows Windows games to be played on other operating systems, with support for Mac OS, Linux and Steam OS. A fast wired network is recommended,but 802.11ac can get the job done.
You can also adjust the streaming quality to suit the connection or display in use.
Dedicated Game Server
For those who like to LAN, an old PC can be used as a centralised game server. This can give a better play experience, and minimises problems with a host machine crashing.
Many popular games have server versions available, including Steam titles. Other options include hosting a voice chat server.