The Mac mini G4 featured a 1.42 GHz G4 processor, 256 MB of SDRAM memory, an 80 GB Ultra ATA/100 hard drive, and a slot-loading 8X DVD/CD-RW Combo Drive. This is the original Mac mini and was sold as a budget Mac that came with no display, keyboard, or mouse. This computer was a great low-cost option for someone switching from Windows to Mac who already owned a display and USB keyboard and mouse.
The Mac mini G4 had ports including DVI (with a DVI-to-VGA adapter included), USB 2.0, FireWire, and a headphone/line out jack. The original Mac mini supported a wireless AirPort Extreme (802.11g) and Bluetooth card as an option. After July 26, 2005, AirPort Extreme and Bluetooth were provided standard.
The entire computer was 6.5 inches square, 2 inches tall, and weighed 2.9 pounds.
From the day the Mac mini was released, I have always had one permanently connected to my living room stereo system and/or flat panel television and used the Mac mini as my iTunes server. I had previously used a Power Mac G4 Cube for this purpose. With this original Mac mini, I was still using a CRT-based TV so I connected to it remotely.
Source: EveryMac.com