Alive Dead Media 2020: Tracker and Chip Music
1st day introduction, Markku Reunanen Pics gracefully provided by Wikimedia Commons
Arrangements
See MyCourses for more details, but for now:
● Whoami, who’s here? ● Schedule of this week: history, MilkyTracker with Yzi, LSDJ with Miranda Kastemaa, holiday, final concert
● 80% attendance, two tunes for the final concert and a little jingle today
● Questions about the practicalities?
History of Home Computer and Game Console Audio
● This is a vast subject: hundreds of different devices and chips starting from the late 1970s
● In the 1990s starts to become increasingly standardized
(or boring, if you may :) so we’ll focus on earlier technology
● Not just hardware: how did you compose music with contemporary tools?
● Let’s hear a lot of examples – not using Zoom audio
The Home Computer Boom
● At its peak in the 1980s, but started somewhat earlier with Apple II (1977), TRS-80 (1977) and Commodore PET (1977)
● Affordable microprocessors, such as Zilog Z80, MOS
6502 and the Motorola 6800 series
● In the 1980s the market grew rapidly with Commodore
VIC-20 (1980) and C-64 (1982), Sinclair ZX Spectrum (1982), MSX compatibles (1983) … and many more!
● From enthusiast gadgets to game machines
Enter the 16-bits
● Improving processors: Motorola 68000 series, Intel
8088/8086/80286
● More colors, more speed, more memory, from tapes to floppies, mouse(!)
● Atari ST (1984), Commodore Amiga (1985), Apple
Macintosh (1984)
● IBM PC and compatibles (1981) popular in the US, improving game capability
Not Just Computers
● The same technology powered game consoles of the time ● Notable early ones: Fairchild Channel F (1976), Atari VCS aka. 2600 (1977), Mattel Intellivision (1979)
● “Video Game Crash” of 1983 ● In the 1980s Nintendo NES (1983), Sega Master System
(1985) and Mega Drive (1988)
● Connection to synthesizers and popular music of the time
- Basic Waveforms
- Noise
● Random noise is also a common waveform on sound chips, it’s just not regular unlike the previous examples
● Useful for percussion instruments, such as snares and hi-hat, sound effects
Beyond the Beeps
● By playing the waveform at different frequencies we get notes. The larger the amplitude, the louder the sound.
● Modifying the frequency and amplitude (i.e. volume) on the fly gives character to the sound
● Turning a waveform simply on and off makes for mechanistic beeps, as real-world sounds aren’t like that
● So-called envelopes control how the volume behaves: fading in and out at different stages. ADSR is one of the simplest ones.
- Attack, Decay, Sustain, Release
- Experiment with Waves and
ADSR
● https://www.keithmcmillen.com/blog/making-music-in-th e-browser-web-audio-midi-envelope-generator/
● Let’s try in practice how different basic waveforms sound like and how applying ADSR changes them
● Might not work on Chrome, try Firefox or some other browser
Real-World Sounds
Example of speech from the Aalto University Wiki
Let There Be Sound!
● Sound was not a priority on the earliest computers – some didn’t even have any sound capabilities
● Not necessarily for games, but for warning beeps ● Game consoles, obviously, were a different ballgame ● Rate generators – one or multiple channels of square wave audio
● Usually just one feature of a clock chip ● A capacitor filters the sound and rounds it ● Often just 8 bits (256 different values) for the frequency
The PC Speaker
● For long the standard PC sound device ● One-channel square wave audio from the clock chip, no volume control, just the frequency
● Quite different implementations across machines ● Tricks: arpeggio, vibrato, even digitized audio using
Pulse-Code Modulation (computationally expensive)
● https://www.youtube.com/watch?v=JzfDOD4q0Kk ● https://www.youtube.com/watch?v=izadA3nSPbk ● https://www.youtube.com/watch?v=wivtSeGr_T8
At Times not Even That
● Sinclair ZX Spectrum – a popular British home computer
(1982)
● Commonly used for games, but: no sound chip, not even a rate generator
● The processor can switch the output on or off: even continuous beeping is heavy. Small internal speaker.
● Pulse-Width Modulation (PWM), interleaving
● https://www.youtube.com/watch?v=BgUzteADsRI ● https://www.youtube.com/watch?v=2lacCH2h70w
Programmable Sound Generators
● Separate sound chips with features like: multiple channels (3 typical), volume control, different waveforms, envelopes
● Still not possible to play digitized audio directly: processor-intensive ramping of volume up and down, amplitude modulation possible
● Used on most 8-bit home computers and game consoles ● Chip music usually refers to this era, either the real hardware or just the general style
General Instrument AY-3-8910
● Or simply just “PSG” ● A typical representative of its kind: three square-wave channels, volume, noise and envelopes
● MSX Compatibles, Sinclair ZX Spectrum 128k, Amstrad
CPC, Intellivision, but also the 16-bit Atari ST
● https://www.youtube.com/watch?v=-TB3j8rlQrU ● https://www.youtube.com/watch?v=ohxzj7rBTDg
MOS Sound Interface Device (SID)
● Used on the Commodore 64 ● Two models: 6581 and 8580 ● More capable than most PSGs: selectable waveforms,
ADSR envelopes, variable pulse width, programmable analog filter and more
● Plenty of famous tunes and composers (see HVSC)
● https://www.youtube.com/watch?v=nhQIotlAxW8 ● https://www.youtube.com/watch?v=k6xhfDLaVtU
● Couldn’t get a SID composer to teach this week, sorry :)
Meanwhile in Japan...
● Well, not just Japan, but rather typically so :) ● Frequency modulation (FM) based chips by Yamaha ● A selection of (sine-based) waveforms whose frequency is modulated by another oscillator
● Complex devices with effects and ADSR envelopes ● Many Japanese arcades, Sega Mega Drive, but also Adlib and SoundBlaster sound cards for the PC computers
● https://www.youtube.com/watch?v=B2aaSG3ICd0
Enter the Amiga
● Commodore’s 16-bit machine (1985), Amiga 500 (1987) very popular in Europe
● Extensive graphics and sound capabilities for the time ● Paula sound chip: no built-in waveforms, but 4 channels of 8-bit digital (PCM) audio with frequency and volume setting
● Stereo sound ● Real instruments from synthesizers, instruments and your favorite albums
● At times called wavetable synthesis
Amiga (cont.)
● The tracker paradigm dominant on the Amiga, tightly reflects the hardware capabilities
● Used for professional music production too ● Digitized samples use much more memory than chip music, Amiga typically had one megabyte(!)
● Playing speech or other “real” sounds no more difficult but a standard feature
● https://www.youtube.com/watch?v=GLMhBE99byM ● https://www.youtube.com/watch?v=Hzx8imUo9kU
And Then
● From 8 to 16-bit samples, CD quality ● Amiga-like wavetable cards enjoyed a momentary success in the mid-1990s: Gravis UltraSound (1992) and SoundBlaster AWE32 (1994)
● Quickly growing processing power made wavetable chips obsolete
● Now simple chips that can just play back digital samples ● Intel’s AC’97 standard (1997): surround sound and 48 kHz sampling rate
Making Music
● What about tools? How did you compose music? ● Initially no particular tools, game music was commonly composed by programming in machine language in the mid-1980s
● https://www.1xn.org/text/C64/rob_hubbards_music.txt
● The musician was often an external person ● Some home computers let users do simple music using the built-in BASIC programming language (=main user interface of the machine)
Back to 1983
● We’re sitting at the living room with our shiny new MSX computer and trying to make it play music
● WebMSX emulator: https://webmsx.org/
● Create music using the play command ● Use an external text editor (not Word or Google Docs) to edit the command and then copy it with alt-b to the emulator – or just use the text box directly
● When done, copy paste it to the Drive
Music Macro Language
● Basic syntax:
play"notes","notes","notes" (you can have up to 3
channels playing)
● Quotation marks must be like this: "
● Notes: cdefgab, # can be used for sharp notes ● Specify the length with a number: c4, 1=full note, 2=half note and so on
● Much more here, if needed:
Concert
● Let’s listen to what the others have composed ● Copy paste from the Google Doc and try to figure out how they did it
Emerging Tools
Soundmonitor (1986) by Chris Hülsbeck for the C-64
The Tracker Paradigm
● The roots of the tracker composing paradigm can be seen
on Soundmonitor already
● Trackers evolved considerably on the Commodore Amiga and were the dominant way of making music, both in the hobbyist and professional circles
● Particularly characteristic software for the demoscene community
● Tomorrow you’ll get to try MilkyTracker yourself.
● https://www.youtube.com/watch?v=dKvreHmHKds
Tracker Basics
The Ultimate Soundtracker (1987) by Karsten Obarski
Another Tracker
FastTracker II (1994) by Triton for the PC