In 1994, Sega decided to enter the lucrative segment of Karaoke services. Sega created a new subsidiary called Sega Music Networks and jointly developed with Taycan and Clarion their first karaoke system under the name Prologue 21. Sega which was already working on their upcoming console, the Sega Saturn, decided to used their newest console as the base for the Prologue 21. The idea made sense as Saturn’s sound source uses a processor called SCSP developed by Yamaha which was a 32-channel PCM sound source with MIDI input / output supporting pitch, echo, etc. It was a perfect chip for karaoke machine.
Released in December 1994, one month after the Saturn, the Prologue 21 was an immediate hit in the karaoke establishments, thanks to the “Song Navigators” (SKH-4000A) manufactured by NEC. At the time, it was still common practice to give customers binders that would contain the list of song available on the device. The “Song Navigators” introduce a touch screen remote that replaced these binders.
The Prologue 21 system consists of many separate parts:
- Amplifier (SKA-3000)
- Commander (SKC-1000)
- Changer (SKA-2000A) which could be expanded to hold up to 100 CD-ROMs. The Changer also support VCDs.
- Wireless Microphone Receiver for Sega-branded SKN-5000 microphones.
- Song Navigators (SKH-4000A)
- Remote (SKY-4100)
As the Prologue 21 was based on the Sega Saturn, it was built so it could also play Saturn’s game by connecting a Saturn controller into the Prologue 21. Although any Saturn controller worked, it was possible to buy Saturn controllers made for the Prologue 21 (SKP-1800). The Commander is the main unit. This is also where the Sega Saturn is hidden. The unit can work in stand-alone if songs are saved on its internal hard drive. It’s to be noted than the Changer (SKA-2000A) cannot be used to play Saturn games.
Saturn Mode: Although the Commander is based on the Sega Saturn hardware, it uses a different BIOS for the karaoke function. Aside the Audio/Video outputs that are shared with the rest of the karaoke function, all other inputs are hidden in two comportment on the front of the Commander. Both of them can be open using a hex key. The first compartment hold the Sega Saturn disk drive while the second hold the controller ports and various other audio adjustments. To launch the Saturn, once the Commander is fully loaded, you need to switch to “Saturn Mode” by pressing a button in the hidden comportment where the controller ports are located. The system will then reboot and you will be able to see the Sega Saturn splash screen. Most unit seems to come with the BIOS 1.00 but some later released may use the 1.01 version (to be confirmed). One of the weird design choices is the lack of a battery in the Commander. This means that the date/time must be entered manually at each boot sequence. It also means that, although you can save your games, they will be deleted once the Commander is shut down.
As the competition was fierce in this market segment, especially with competitors such as Daiichi Kosho and XING releasing new models one after another, Sega had to quickly released an updated version of the Prologue 21 called the Super Prologue 21.