DFRobot ST7735 Display128x160 SPI - Won't work

Hello, I have a number of DFRobot ST7735 128x160 displays and I cannot get them to work at all.

I have to use an Arduino Mega.

I have used the test program in Wiki and connected VCC, GND and TFT_DC , TFT_CS and TFT_RST to 2,4,3 and wired them up correctly.

The DFRobot test program only defines these 3 signal cables. Don't I need SCLK, MOSI etc? In which case where do I wire them to?