OPL2LPT-Replica

Introduction

OPL2LPT-Replica is a re-designed, open-source simplified version of OPL2LPT circuit board with fewer components under MIT license, acting as a YM3812 FM synthesizer on LPT port, and fully 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 in gerbers folder, so that PCB samples can be easily manufactured

  https://www.jlc.com/ is recommended to order PCB samples in China

  

Bill of Material

Component	Designator	Quantity	Note & Possible Sources
Leaded 100pF (101) MLCC	C1	1	Mouser 594-K101J15C0GF5UH5
Leaded 100nF (104) MLCC	C2	1	Mouser 594-K104K15X7RF5UL2
Leaded 10uF Pol. Cap.	C3, C5, C6	3	Mouser 667-ECA-1EM100
Leaded 2.2uF (225) MLCC	C4	1	Mouser 81-RDER71H225K2M1H3A
Leaded 3mm Green LED	D1	1	Mouser 630-HLMP-Y801-JPP00
74HC04 CMOS Inverters	IC1	1	Mouser 595-CD74HC04E
Yamaha YM3014B DAC	IC2	1	https://www.aliexpress.com/item/32611185781.html, DIP-8 socket is recommended
Yamaha YM3812 OPL2	IC3	1	https://www.aliexpress.com/item/32595976031.html, DIP-24 socket is recommended
LM358 Dual OP Amp	IC4	1	Mouser 595-LM358AP
Leaded Mini USB Type B Connector	P1	1	Mouser 571-2172034-1
D-Sub 25P R/A Male Connector	P2	1	Mouser 523-L717SDB25P1ACH3R
Header 2P 2.54mm	P3, W1	2	Mouser 855-M20-9990246
3F07 3.5mm Stereo Audio Jack	P4	1	https://www.aliexpress.com/i/32478957056.html
1k 1/4W Resistor	R1, R2, R3	3	Mouser 279-YR1B1K0CC
10k WH148 Potentiometer	R4	1	https://www.aliexpress.com/item/32998649900.html
10k 1/4W Resistor	R5, R6	2	Mouser 279-YR1B10KCC
TSW DIP-6*6*11 Key	S1	1	https://www.aliexpress.com/item/32725384168.html
Crystal HC-49S 3.58MHz	Y1	1	Mouser 449-LFXTAL032257BULK

Notes for Assembling & Testing

• 5V DC power is needed, either from Mini-USB port or external power pins

• Try to press RST SW to apply a manual reset when YM3812 behaves abnormal

• Detailed parameters for components are noted on the board's silkscreen

• Crystal must be 3.58MHz for accurate pitch of notes

• Using 74LS04 to substitute 74HC04 for the Pierce oscillator is not recommended

  Note: If the oscillator doesn't work, replace the two 1k ohms resistors around the 74HC04 IC with higher value resistors such as 4.7k ohms. Fine tuning for 100pF (101) MLCC capacitor around the 74HC04 may be also needed.

• 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 part of DOS games

  • on Windows 3.1: https://github.com/andreiw/adlib21

Update Logs

• Version 0.1(beta): First PCB for debugging

• Version 0.2(beta):

  • A smaller re-designed PCB
  • Audio quality improved

• Version 0.3(beta): Fix unconnected GND net for 3.5mm audio jack

• Version 1.0:

  • First version updated on https://github.com/
  • Fix power LED & volume control's problem
  • Use a round PCB corner for easier assembling (with a 3D-Printed case)
  • Pull-up resistors on bus are removed to improve compatibility for some old PCs
  • Use non-SMT Mini-USB port, making it easier to solder by hand
  • Add external 5V-DC power pins

• Version 1.0.1:

  • Add 3D-Printed case (with cover) and knob

    Thanks for @zhblue for your awesome *.stl models

  • Change directory structure for GitHub repo

• Version 1.1.0:

  • Fix clock problem caused by unsuitable resistors and capacitor for Pierce oscillator
  • Add Bill of Material and some images for this README document
  • Export PDF version for schematic and PCB documents