The original design for this computer interface comes from Mironics.
The following parts are required. All resistors used should have a tolerance of 1% or better (ie use metal film resistors, not carbon film). In Australia, I recommend purchasing components from Jaycar Electronics.
- 1 * 43 ohm Resistor
- 1 * 56 ohm Resistor
- 1 * 200 ohm Resistor
- 1 * 270 ohm Resistor
- 2 * 1k Resistor
- 2 * 1.3k Resistor
- 4 * 1.5k Resistor
- 2 * 1.8k Resistor
- 1 * 2.k Resistor
- 1 * 2.7k Resistor
- 1 * 5.6k Resistor
- 1 * 10µF electrolytic capacitor
- 1 * 0.01µF ceramic capacitor
- 1 * 4051 (or CD4051) 8 way analogue multiplexer
- 4 * 1N4148 signal didode
- 1 * 16 pin IC socket (optional)
- 1 * D25 male connector
The circuit needs to be assembled according to the schematic diagram below. You can make your own pcb according to the design below, or use a prototyping board of some kind. The connector to the Minidisc unit can be obtained from an old Discman or MiniDisc remote control, or made using a pcb or piece of veroboard.
Note: The pin numbers on the MD unit 4-pin plug are "1" to "4" starting from left (near the stereo headset plug) to right.
Robert Horvath has kindly contributed the following pcb design:
My completed interface looks fairly messy built on some veroboard, but fits inside a DB25 backshell:
