Marlin Firmware

Hi guys, Another 'Newbee' problem.
Ive built my Rostock printer. I am trying to download the marlin V1 firmware to my Arduino mega /RAMPS 1.4.. I'm following the 'Configuration and Compilation' guidance, on 'Github.com/jcrocholl/Marlin/tree/marlin_V1 webpage.
I'm at 'Start the arduino IDE. Select Tools -> Board -> Arduino Mega 2560 or your microcontroller Select the correct serial port in Tools ->Serial Port Open Marlin.pde' . . . and I cant find the marlin.pde file in the downloaded marlin directories..
Anyone know where I've gone wrong?

Have you got Marlin.ino, that is what it is called for later versions of the Arduino IDE?

---

[www.hydraraptor.blogspot.com]

No; there's no 'marlin.ino' either. Have attached a screengrab of the file names in the directory; there are 5 with 'marlin' in the name. One (with no extension) is a 'processing source code' file ?!? Others following this procedure must have found the file elsewhere?

The one with no extension is your .pde, windows is 'helpfully' hiding known extensions to protect you from scary technical details. You can turn that off, google 'hide known file extensions' to find instructions for your flavour of windows.

Many thanks. Sure enough, those splendid windows people had hidden the extension; Ooohhh I laughed.