OPL2LPT-Replica

Introduction

This is a re-designed, open-source simple version of OPL2LPT circuit board with few components, acting as a YM3812 FM synthesizer on LPT port (Adlib Card Compatible).

Buy the original version of OPL2LPT and for more info: https://www.serdashop.com/OPL2LPT.

Development & Manufacture

Please use Altium Designer 16 or above to open or edit the PCB project
Gerber files and NC drill files are already exported. PCB samples can be easily manufactured

https://www.jlc.com/ is recommended for ordering PCB samples in China
Using 74LS04 (TTL) to substitutes 74HC04 (CMOS) for the clock generator is not recommended, and may causing the circuit's failure
XTAL must be 3.58MHz for accurate pitch of notes
Parameters for components are noted on the board's silkscreen. More info in the PCB project

Notes for Testing

5V DC power is needed, either from Mini-USB or external power pins
Manually reset (RST SW) is needed when YM3812 behaves abnormal
Available open-source drivers for this project:
- on MS-DOS: https://github.com/pdewacht/adlipt (working fine using either method below)
  - Using TSR adlipt for port mapping (with emm386.exe)
  - Using adpatch to patch some DOS games
- on Windows 3.1: https://github.com/andreiw/adlib21 (without testing)

License

MIT license is chosen for this project.

Update

Ver 0.1(beta):First PCB for debugging
Ver 0.2(beta):
- A smaller re-designed PCB
- Audio quality improved
Ver 0.3(beta):Fix unconnected GND net on 3.5mm audio jack
Ver 1.0:
- First version updated on https://github.com/
- Fix power LED & volume control's problem
- A round PCB corner for easier assembling (with a 3D-Printed case)
- Pull-up resistors on bus are removed to improve compatibility for some PCs
- Use non-SMT Mini-USB port, making it easier to solder by hand
- Add external power pins
Ver 1.0.1:
- Add 3D-Printed case (with cover) and knob (thanks for @zhblue for your awesome *.stl models)
- Update directory structure for GitHub repo