Rob soldered a header of pins on the LCD module and a header on a separate PCB board. A ribbon cable connects the LCD to the PCB. The wires from the parallel cable are soldered to the PCB. The 2 pots are also mounted on the PCB.
The +5v (and GND, to drive the backlighting) for my display comes from the red wire and matching black wire half of a power connector from the computer power supply (intended for an internal device, typically used for hard drives and CD-ROM drives). Use a volt meter to make sure you get the proper lines! The other pair I believe supplies 12v which will more than likely blow your display.
| DB25 | LCD | *** | DB25 | LCD |
| 1 | E | 14 | R/W | |
| 2 | DB0 | 15 | NC | |
| 3 | DB1 | 16 | RS | |
| 4 | DB2 | 17* | E2 | |
| 5 | DB3 | 18 | GND | |
| 6 | DB4 | 19 | GND | |
| 7 | DB5 | 20 | GND | |
| 8 | DB6 | 21 | GND | |
| 9 | DB7 | 22 | GND | |
| 10 | +5V | 23 | GND | |
| 11 | +5V | 24 | GND | |
| 12 | GND | 25 | GND | |
| 13 | GND |
Pins 10 and 11 don't need the +5V, you can leave them with No Connection (I have no idea why mine is wired that way).
*Note that only 40x4 displays have a second enable line. For displays with no E2, there is no connection for pin 17.
The 2 pots are used to control the brightness (LED power) and contrast (Liquid Crystal Driving Voltage) of the display.
1 - (Vss) Ground
2 - (Vcc) Power Supply (+5 volts) (Vdd on my Seiko data sheet)
3 - (VLc) Liquid Crystal Driving Voltage
15 - (VB+) LED Power (Anode) (+5 volts) (Va on my Seiko data sheet)
16 - (VB-) LED Power
(Cathode) (Vc on my Seiko data sheet)
Match up the DB25 pin to the VFD pin by consulting the datasheet with the pinouts for the VFD. The only other connection for the VFD is the +5v and GND to drive the unit.
| DB25 | VFD |
| 2 | D0 |
| 3 | D1 |
| 4 | D2 |
| 5 | D3 |
| 6 | D4 |
| 7 | D5 |
| 8 | D6 |
| 9 | D7 |
| 11 | Busy |
| 14 | WR |
Please do NOT e-mail me if you can't figure out how to hook up your display.