If you want to play Dreamcast or Saturn games online via dial-up modem, you’ll need a live phone line (with electrical current running through it) in order to carry the analog phone signal from the Dreamcast/Saturn Modem over to the USB Modem connected to DreamPi or PC Server. Live phone lines were once common in every household across the globe, however, today we have to “fake it” and create our own. There are two common options for doing this:
OPTION A: VoIP Adapter + Splitter – There’s a good chance you may already have one of these old Linksys VoIP adapters lying around, especially if you already tried your hand at the previous VoIP method, now replaced by this new superior tunneling method. Believe it or not, these actually generate continuous line voltage when they are connected to power but not connected to ethernet. All you need to do is plug a phone line splitter into the VoIP adapter, and then send one phone cable to the NetLink Cartridge and another phone cable to the USB modem. Voila! Line voltage!
(Disclaimer: this solution works fine, but it’s perhaps the messiest solution (what with the adapter, splitter, phone cables, power brick, etc…) If you prefer a cleaner setup, consider options A or B)
OPTION B: Build a Line Voltage Inducer – If you don’t want to spend the money (and you have basic soldering skills), you may wish to build your own Line Voltage Inducer. It may not be as simple and clean a solution as the above, however, you can make it as neat and tidy as you wish… You find individuals on Etsy or eBay selling them pre-made (subject to availability).
Here, we’ll show you how to build your own Line Voltage Inducer.
DIY Line Voltage Inducer
To build a line voltage inducer you will need the following components:
- RJ11 telephone cable (10-15 ft.)
- 0.47uf electrolytic capacitor
- 330 – 380 Ohm resistor
- 9v battery connector
- 9v battery
- Solder (and soldering iron)
- Heat Shrink (or Electrical Tape)
First, you will cut the outer shielding from a 3-4″ inch length of the phone cable (be careful not to cut the wires inside).
Inside the cable, you will typically find four wires (red, black, green & yellow – we will be dealing with the red wire only and leave the others alone). Cut the red wire in the middle and strip the ends of the red shielding so that the wire is exposed at each end.
Then, connect the electrical components by soldering them according to the diagram below:
It’s best to apply heat shrink where any two wires have been soldered in order to properly insulate the connection, however, electrical tape may be used as well. Once all components have been assembled and shielded, you may wrap the entire area of the cable with heat shrink or electrical tape as well.
If you prefer a tidier result, you might consider picking up a cheap phone line coupler from Amazon or any hardware store, crack it open, and perform the above soldering connections to the red wire housed within.
If you are using this guide for online play with a PAL Dreamcast, the PAL Dreamcast modem will require more line voltage. Here is a modified wiring diagram that incorporating two 9v battery connectors. IMPORTANT: DO NOT USE THIS WITH A SEGA SATURN MODEM AS IT COULD CAUSE PERMANENT DAMAGE.
