Futaba MDM166A
This display was used on some Targa computers and is connected by USB (Vendor ID 0x19c2; Product ID 0x6a11). The display got an microcontroller offering an internal clock (no battery backup), 96×16 full graphics and some symbols. It can be driven using LCDHype and the included driver. The power supply of 5V comes from the USB port (CN1) and a molex floppy connector (CN2), which is just used for detecting the startup of the computer. This connector can be left unconnected, except pin 1 which has to be wired to pin 1 of the USB connector (CN1). This modification allows the usage with just a USB connection. The complete load seems to be driven by the USB connection (370 mA showing all symbols and pixels). The commands are very simpel and easy to implement.
Connector CN1 (USB):
| CN1 pin | USB signal | Colour |
|---|---|---|
| 1 | Vcc (+5V) | red |
| 2 | Ground | black |
| 3 | D+ | green |
| 4 | D- | white |
Connector CN2 (Floppy Powersupply):
| CN2 pin | Signal |
|---|---|
| 1 | Vcc (+5V) |
| 2 | Ground |
| 3 | Ground |
| 4 | no pin (Rev. C) not connected (Rev. D) |
There are some debug points near to the microcontroller on the PCB named with RS232C signals. I will try to communicate via the serial communication next days. The USB connection seems to be the master interface – the serial interface does not work. It is some kind of difficult to power up the display if the USB interface is not used. I cancelled my tries with the serial interface. The USB interface is even better and faster so there is no need for it.
The small hole in the base glass substrate on the right side next to the volume bars lead to some rumors that it could implement an IR sensor. Sorry, but this is just the place where the tube was evacuated in the production process. There is no IR sensor or something else there.
Download
LCDHype driver: Futaba MDM166A v1.7
Futaba MDM166A documentation v1.1