Monthly Archives: June 2014

Shooting & Dodging

When Space Invaders was released way back in 1978, invariably it would lay down the fundamentals of the shooting game genre. We may refer to this genre simply as shooting games, shmups or even STG’s as the Japanese prefer to call them.

The Grand Daddy of shooting games
The Grand Daddy of shooting games

However, I wish to clear something up first. A game like Space Invaders is not a shmup in the true sense. This is often a reference to shooting games that have a forced scrolling background either horizontally or vertically. At the very least, Taito’s Space Invaders can be defined as a proto-shmup for lack of a better term.

Genre categories and deviations are not that important right now. The core game mechanics of all shooting games are similar. As the title of this post clearly indicates, it’s all about shooting and dodging. Simple really, almost primal. That’s the main draw after all, shooting the enemy while avoiding  getting hit yourself.

Computers have always been able to handle shooting games incredibly well. It’s a piece of cake for even underpowered systems to make things appear and disappear on screen. All this may give the impression that developing  a shooting game is easy peasy!

If only that were the case. Simplicity should never be underestimated in regards to making things – easier. It takes some deft skills and an elegant touch to piece together a playable shooting game. Developing one for commercial release will often require months of play-testing and polish.

Shooting games also demand a sharp eye for detail. Not just the visual aspect, but also every single enemy placement, every movement and every pattern. And it doesn’t stop there, every bullet that will be fired, direction of fire and even colour, size and damage it can inflict all have to be taken into account. In some cases, these can all total up to over a hundred sprites on screen at once.

With so much happening on the screen, there is plenty that can go wrong. The worst in my opinion is leaving very little wiggle room for the player. So incredibly confined that a direct hit is often unavoidable, thus rendering the game either unfair or unplayable. Reducing the size of the player sprite hitbox is a common solution. My preferred method to solve this issue is smart enemy placement and firing rates.

There are various other solutions, but I won’t go further now. What’s vital is ensuring that shooting and dodging are both fun. It’s essentially the yin and yang of the majority of shooting games and what makes them addictive.






Bass Cadet 01 – Thunder Force IV

Welcome to my new weekly feature – Bass Cadet.

Every week I will be showcasing a piece of music that’s relevant to the retro enthusiast right here on Bass Cadet. Requirements and criteria for a me to cover a single track, album or even a live performance are as follows:

  • Composition must be strictly electronic.
  • The production may be for a game or any other medium but it must be able to work as a game soundtrack.
  • Vitally important for all compositions to be instrumental but samples and singing are permitted, provided they are a good match.
  • Experimental compositions are allowed but they must be listenable.
  • It may be an old or new production but it must sound positively retro.
  • Last but not least, it must sound great!

Now that I’ve got that out of the way, let’s kick off this week’s feature with something awesome. Technosoft (also known as Tecno Soft) were the code house behind the truly remarkable Thunder Force series. They were also know for the astounding sound work on their game releases.

Thunder Force IV on the Sega Mega Drive (Genesis for those in the U.S.) is one of my favourite horizontal scrolling shmups of all time. It’s just one of those games that strikes the right balance between visuals, sound and play mechanics. A masterpiece bar none.

Since TFIV was developed for the Mega Drive the music is obviously using the system’s Yamaha YM2612 FM-based chip. The previous article covered FM-Synthesis and gave some excellent examples of it’s applications.

However, Thunde Force IV is the standard-bearer for FM-Synthesis on the Mega Drive. Composed by Takeshi Yoshida, Toshiharu Yamanishi and Tomomi Otani they managed to put that little Yamaha chip through it’s paces. If you click on the video above, the results speak for themselves. Fusing techno-jazz with metal, this can only be described as 16-bit cyber thrash, space orchestra. Enjoy!













FM Synthesis & Video Game Music: A Brief History

I would like to start this article by thanking Demos at 16-BIT Shock for the opportunity to write a series on FM Synthesis within video game audio for his blog. It’s a great opportunity and I hope everyone that reads it will find the articles informative and helpful. This first article is primarily going to give an overview of FM synthesis within video game audio, popular chips used within consoles, and also a brief overview of how FM synthesis works.


How FM Synthesis Works (simplified):


Whereas subtractive synthesisers use fixed waveshapes as the basis for their sounds, Frequency Modulated synthesisers create sounds by modulating (changing) waveforms with the frequency of another. The most simple set up is having one carrier wave and then the modulator wave which modulates the frequency of the carrier wave (see image below).

Popular sounds created by FM synthesis are those of the organ, electric piano, plucked instruments and pitched percussion. However as operators per channel increases so can the complexity of the sounds.

8-bit chiptunes largely consist of basic waveforms such as square, pulse, sawtooth and triangle. And basic percussion sounds could then be provided by using a white noise generator through an ADSR envelope, or through FM synthesis. However, as chips advanced and the number of operators and channels increased, so could the sounds produced using FM synthesis.

To understand how to make FM synthesised sounds though we first need to learn how it works. In later articles I will be delving into the detail of creating various sounds. By looking at some of the maths behind FM synthesis, you can quickly obtain a good understanding of how flexible it is a generator for wide array of sounds.




A History Lesson (but not a boring one):


Frequency Modulated (FM) synthesis was developed by John Chowning throughout the late 1960’s, and eventually patented in 1975. It is a form of audio synthesis that allows the production of complex sounds within a digital environment, rather than requiring analog hardware. In the 1970’s and 80’s this meant complex synthesised sounds could now be produced within digital apparatus, and not using physical hardware like analog synths required.

In 1977 Yamaha licensed the patent and by utilising the technology manufactured chips. Through manufacturing chips that became the cornerstone of FM synthesis within video game consoles, and producing the very famous DX7 synthesiser, Yamaha became respected as the purveyors of Frequency Modulated synthesis. It was FM chips that when implemented into gaming consoles allowed greater flexibility with regards to audio and required little memory power. Therefore resulting in more expressive music with minimum constraints on the machines themselves.

By the time 1983 rolled around and everyone was donning Mad Max attire, Konami’s ‘Gyruss’ was utilising five FM synthesis chips for in game music. Playing some Johann Sebastian Bach in all its glory it displayed the array of voices that could be utilised –


FM synthesis was one of the major advances in consoles for the 16-bit era and in 1988 Sega introduced the Mega Drive (Genesis). This was the first 16-bit game console to come to market, as well as the first to feature a Yamaha FM chip, the YM2612.

The greater flexibility of using FM chips gave way to more intricate compositions, and two highly regarded composers of FM synth video game music are Yuzo Koshiro and Takeshi Abo. As one of the major chiptune composers of the time, Yozu Koshiro produced music for Shinobi, The Revenge Of Shinobi and Streets Of Rage, to name a few. His Streets Of Rage 2 soundtrack was considered ahead of its time and revolutionary in its composition.


Chipping Away:


As Yamaha were viewed as the purveyors of FM synthesis and their chips were so widely used, I thought it would be appropriate to look at their chips in a bit more depth. I will give a brief overview of the most popular chips, and where possible give examples of what some of the audio from them sounded like.

Yamaha YM2203

– Notable uses: A variety of NEC computers alongside various arcade machines

– Three FM channels (voices)

– Four operators per channel

– FM sine wave operators

– Audio:

Yamaha YM2608

– Notable uses: NEC’s PC-8801/PC-9801 / Megadrive

– Successor to YM2203

– Sixteen channels overall

– Six FM channels

– Four operators per channel

– Three channels of square wave synthesis via implementation of YM2149/SSG

– Single channel for 8-bit sample play back

– Rhythm Sound Source: six channel percussion playback system

– Audio:

Yamaha YM2610

– Notable uses: SNK’s Neo Geo arcade and home game systems

– Fifteen channels

– Four FM channels

– Three channels of square wave synthesis via implementation of YM2149/SSG

– A total of seven ADPCM (pulse code modulated) channels

– One noise channel

– Single LFO (low frequency oscillator)

– Audio:

Yamaha YM2612

– Notable uses: Genesis / Megadrive

– Stripped back version of the YM2608

– Six FM channels (voices)

– Four operators per channel

– Sine wave low frequency oscillator

– Audio:

Stay tuned for the next article where we will discuss the creation of two key drums sounds. The kick drum and toms. I will be explaining in more depth how FM synthesis and it may be wise to have a calculator handy. In the mean time, wrap your ears around some music made exclusively from FM synthesis:


Joe Gilliver – BA Hons (Ocular Audio)

Composer | Producer | Sound Designer