Willy

Willy - MIDI and OPL3 Soundcard adapter for CPC

Demonstrations

• Willy OPL3 on a real CPC demoed by Prodatron
• Willy MIDI and Willy OPL3 emulated on ACE demoed by Offset
• Willy OPL3 emulated on ACE-DL demoed by Roudoudou
• OPL3LPT soundcard reviewed on PC by ChinnyVision

Weblinks

• https://pulkomandy.github.io/shinra.github.io/willy.html
• OPL3 Player Pack Huge pack containing 3887 OPL2/OPL3 tunes to be played on Amstrad CPC

Cost

The cost for a Willy soundcard adapter is 10€. This does not include any soundcard, you have to buy those separately.

Technical information

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.

OPL3 is register compatible with OPL2, with twice the number of signal sources, 4 new operator modes, 4 new selectable waveforms (including square wave) and stereo output.

OPL3 offers 18 FM 2-op chans in its standard mode, but that can be configured:

• One setting converts 3 of the FM chans into a 5-chan FM percussion set
• Another setting pairs 12 of the FM chans into 6 FM 4-op chans
• Both settings can be used at the same time, to obtain 6 FM 4-op chans + 3 FM 2-op chans + 5-chan FM percussion set

FM Percussion Set

The OPL3 synthesizes drum sounds using a combination of frequency modulation (FM) synthesis and bit manipulation, which works as follows:

• Bass Drum: Uses FM synthesis between operators to generate a low-pitched percussion sound
• Tom Tom: Direct output of a single operator, with no modulation
• Snare Drum: Combines the phase of a single operator with random noise, mimicking a snare's sharpness
• Cymbal: Created by XOR-ing six bits from the phase of two operators, producing a noisy waveform
• Hi-hat: Similar to the cymbal, but with added random noise for a sharper, metallic sound

Compatible Serdaco soundcards

• S2P soundcard aka Roland MT-32 or General MIDI Wavetable Synth - Datasheet
• OPL3LPT soundcard aka AdLib Gold or Sound Blaster 16 - Datasheet
• OPL2LPT soundcard aka AdLib or Sound Blaster - Datasheet
• CMSLPT soundcard aka Creative Music System or Game Blaster - Datasheet
• TNDLPT soundcard aka PCjr or Tandy Sound - Datasheet
• CVX4 soundcard aka Covox Speech Thing - Technical analysis