Thanks, I found the message with the required changes to "flip" the output of the screen upsidedown.
Sidetone : If you ever need a compact (text only) SSD1306 library I can recommend the library from Bill Greiman
http://www.esp8266.com/viewtopic.php?f=29&t=7841&p=39726&hilit=wemos#p39726
Works a treat on Arduino and ESP.
Thanks for starting this topic, gave me a jump-start using the SSD1306 Oled display.