One of the goals of this website is to introduce people to the various video game consoles and their sound capabilities. Let’s talk about the Sega Genesis.
A Brief Description
Known as the Sega Mega Drive in Japan and as the Genesis here due to copyright restrictions on the name “Mega Drive”, the Sega Genesis was the first 16-bit gaming console released in the US, though not by much (it only bested NEC’s Turbografx-16 by 14 days). It featured a huge library of 915 game cartridges, stereo output sound, and numerous add-on console enhancements including the Sega CD (a CD-ROM drive attachment) and the Sega 32x (a 32-bit gaming console attachment). It was Sega’s best selling console of all time (though Sega has refused to report how many units were sold officially). The last Sega Genesis rolled off the line in 1997, when the console was retired. For more information, check out: http://segaretro.org/Sega_Mega_Drive
The Sega Genesis was built off the original Sega Master System motherboard (an 8-bit console developed by Sega- I’ll talk about this later). The main processor for the system was the legendary Motorola 68000 which was used in many arcade console machines and Apple Macintosh computers. Since the Genesis motherboard is actually BUILT from Master System board (like, literally the same board with modifications), the Motorola 68000 is assisted by a Zilog Z80 “coprocessor”…. which is actually just the processor from the Master System. In this capacity, the Z80 is used almost exclusively to control sounds and audio. (A nerdy aside – the Motorola 68000 goes on to serve as the sound processor for the Sega Saturn – the proccessor circle of life).
As for the sound chips themselves, the Genesis utilized the Yamaha YM2612 and the Texas Instruments SN76489. The SN76489 was simply the Master System audio chip that was left over after editing the board. It had three square waves and a noise channel (very similar to the NES sound chip, the 2A03). By adding the YM2612, the Genesis gained 6 channels of FM synthesis, with the 6th channel capable of being used as a DAC (digital to analog) converter. Through the use of these two complimentary sound chips, the audio system for the Genesis was capable of playing 6 concurrent sounds while using the SN76489 for sound effects (like jumping, bumping, running, grabbing rings, etc). Very powerful stuff.
Lastly, the Genesis, just like the Nintendo Famicom, had two pins inside the cartridge reader just for sound expansion modules. Sadly, not a single Genesis game utilized this and no sound expansion modules were ever developed for the Genesis.
Essentially, the 6 FM synthesis channels of the Genesis allowed for many varied sounds. FM synthesis allows one to customize or modulate the frequencies of the sounds to create almost infinite possibilities (hence frequency modulation synthesis). In addition to that, the Genesis could always use the 8-bit sound chip to create three pure square waves or noise. This gave the Genesis the best of both worlds – an arcade-like FM synthesis sound chip AND an 8-bit audio chip. Let’s take a look at some classic Genesis music. Here’s Sonic the Hedgehog “Green Hill Zone”:
Pretty awesome. How about more awesome? Noriyuki Iwadare (who I wrote about here) wrote the soundtrack to Warsong (Langrisser in Japan), an awesome strategy RPG:
I really love the utilization of all the different sound effects. The drums are impressive for 1991. Just a great track. Finally, I’ll post what I consider to be one of the most complex pieces of music for the Sega Genesis- a track from Sonic the Hedgehog 3 – “Final Battle”:
What I think is so great about this track is the utilization of the 8-bit audio chip for the backgrounds. We’ll talk more about Howard Drossin later – he’s awesome.
The Sega Genesis may be remembered for its massive collection of arcade game ports, Sonic the Hedgehog, or numerous unique sports games. Still, I think people may remember it as being the console they owned that made their NES owning friends jealous. I chose to remember it for its impressive sound capabilities and a version of Mortal Kombat that actually had blood in it. Whatever you remember it for, it was an important console in the history of gaming that changed the landscape forever. I hope you found this informative. I welcome your comments.