Willy - [[MIDI ]] and OPL3 Soundcard adapter for CPC It is the spiritual successor of the [[CPCISA]] project.
[[File:Willy1.jpg]]
== Weblinks ==
* https://pulkomandy.github.io/shinra.github.io/willy.html
* [http://www.roudoudou.com/ACE-DL/ OPL3 Player PackArchive ZIP] Huge pack containing 3887 OPL2/OPL3 tunes to be played on Amstrad CPC
* [https://opl.wafflenet.com/ The OPL archive] [https://vgmrips.net/packs/chip/ym3812 VGMrips OPL2] [https://vgmrips.net/packs/chip/ymf262 VGMrips OPL3]
<br> == Cost ==The cost for a Willy soundcard adapter is 10€* [http://tgv777. This does not include any soundcard, you have to buy those separatelyfree.fr/index.php/fichiers-midi/ MIDI Files] [https://musical-artifacts.com/artifacts?order=most_downloaded&q=midi+soundfont MIDI SoundFonts]
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== Compatible Serdaco soundcards ==
*[https://www.serdashop.com/S2P S2P soundcard] aka Roland MT-32 or General MIDI Wavetable Synth Synthesizer - based on SAM2695 (2014) - [[media:SAM2695.pdf|Datasheet]]*[https://www.serdashop.com/OPL3LPT OPL3LPT soundcard] aka AdLib Gold or Sound Blaster 16 - based on OPL3 (1990) - [[Media:YMF262 199110.pdf|OPL3 Datasheetdatasheet]] [[Media:Yamaha yac512 datasheet.pdf|DAC datasheet]]*[https://www.serdashop.com/OPL2LPT OPL2LPT soundcard] [https://github.com/zjuyzj/OPL2LPT-Replica OPL2LPT-Replica] aka AdLib or Sound Blaster - based on OPL2 (1985) - [[mediaMedia:Yamaha_YM3812.pdf|DatasheetOPL2 datasheet]] [https://c64.xentax.com/media/Yamaha_YM3812_Application_Manual.pdf OPL2 application manual] [[Media:YM3014 DAC datasheet.pdf|DAC datasheet]]*[https://www.serdashop.com/CMSLPT CMSLPT soundcard] aka Creative Music System or Game Blaster - based on two SAA1099 (1984) - [[media:Philips_saa1099.pdf|DatasheetPhilips datasheet]] [[media:Mullard-saa-1099 datasheet.pdf|Mullard datasheet]]*[https://www.serdashop.com/TNDLPT TNDLPT soundcard] aka PCjr or Tandy Sound - based on SN76489 (1979) - [[media:Texas_instruments_sn76489an.pdf|Datasheet]]
*[https://www.serdashop.com/CVX4 CVX4 soundcard] aka Covox Speech Thing - [https://scalibq.wordpress.com/2017/11/28/the-covox-years/ Technical analysis]
Note: Unlike Like the MIDI synth functionality of the [[AMSDAPRSF3]] OPL4 & YRW801 ROM solution, the S2P soundcard natively supports Wavetable MIDI without requiring . It doesn't require a software translation layer. The Willy with S2P soundcard recreates what it was like to connect an Amstrad CPC via a the [[Music MachineAMSDAP]] MIDI port to a Roland MT-32 synthesizer in 1987OPL4 & YRW801 ROM solution.
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== I/O Ports ==
2 ports are used to control the [[MIDI ]] soundcard: &FEAC for data, and &FEAD for control and status.
3 ports are used to control the OPL3 soundcard: &FEBC and &FEBE are register select ports, and &FEBD is the data port.
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=== Logsin and Exponent tables Algorithm ===
The OPL chips generate sound efficiently, without using any multiplication or other costly arithmetic operations. Instead, they use two look-up tables, (exp and logsin) each containing 256 entries. [https://g.co/kgs/Da1vEi4 Source]
They produce the sound without any multiplication or other costly arithmetic operations, using The tables are used in this formula for 2-op "frequency modulated" (actually phase modulated) synthesis the formula:
out = exp(logsin(phase2 + exp(logsin(phase1) + gain1)) + gain2)
When such a table is used for calculation of the exponential, the table is read at the position given by the 8 LSB's of the input. The value + 1024 (the hidden bit) is then the significand of the floating point output and the yet unused MSB's of the input are the exponent of the floating point output.
==== Log-sin Logsin table ====
x = 0..255, y = round(-log(sin((x+0.5)*pi/256/2))/log(2)*256)
* Western PC game developers in the early 90's also tended to produce music by using a master MIDI track on Roland MT-32, and then downgrading it for the various PC soundchips. The result was a cheesy so-called "MIDI" music. That was unfair for OPL3 (but also for MIDI, as Wavetable MIDI sounds way better than that).
=== Examples of proper OPL3 music : [https://www.youtube.com/watch?v=a7I-QmrkAak MoonDriver] [https://www.youtube.com/watch?v=uyVOy02tW88 Paul the Penguin] [https://www.youtube.com/watch?v=6JlFIFz1CFY Zen Challenge] <br> ==Links ==
* [https://wwwmoddingwiki.youtubeshikadi.comnet/watch?v=a7I-QmrkAak MoonDriverwiki/OPL_chip Programmer's guide to OPL3]*[https://g.co/kgs/Da1vEi4 OPLx decapsulated]* [https://www.youtuberighto.com/watch?v=uyVOy02tW88 Paul the Penguinsearch/label/dx7 Yamaha DX7 chip reverse-engineered]from die shots* [https://wwwyoutu.youtubebe/BCwn26FePAo Yamaha DX7 - Famous Sounds Demo] Yamaha FM synthesis chips defined the sound of the 1980s*[https://youtu.combe/watch?v=6JlFIFz1CFY Zen ChallengeTVmZarPUc-Q Korg M1 Famous Songs and Sounds]Wavetable synthesizers dominated in the 1990s
[[Category:Music and sound]] [[Category:Peripherals]] [[Category:Hardware]]