I am trying to compile your excellent BASIC from GitHub and am close, but have a problem.
Which exact version of Arduino 1.6.5 are you using? 1.6.5, 1.6.5-r2, 1.6.5-r3, 1.6.5-r4, or 1.6.5-r5?
Version 1.6.5, which you mentioned, has no Windows installer .exe file, AND the .zip file has no Arduino application Arduino.exe to run. The only version with a Windows installer is 1.6.5-r5, so I used that to get started. (It's .zip file has an Arduino.exe.)
In the Aduino app's Preferences, "Additional Boards Manager URLs" field I put the URL you specify:
http://arduino.esp8266.com/versions/2.3 ... index.json
Then I used the Arduino app's Board Manager to select and install the "esp8266 by ESP8266 Community" version 2.3.0.
For the ESPBasic interpreter, I downloaded from GitHub the latest version Basic-NewWindowsSockets.zip (8/22/16). I put it's ESPBasic folder in the Arduino's projects path as
\My Documents\Arduino\ESPBasic.
I put its libraries folder as
\My Documents\Arduino\libraries.
Now my problem is that the bin I compile gives me a byte count of 488,683 for the Sketch + 47,432 for Global Vars, for a total of 536,115, which differs from the byte count using the ESP_Basic_Flasher. (I compiled for both NodeMCU board options; for Generic ESP8266 Module got a compile error.)
When I used the ESP_Basic_Flasher.exe version 0.0.0.0 to get the binary from the web, with upload parameters COMM4 and 4MB, it said,
"Uploading 499408 bytes from .\build\4M\ESP8266Basic.cpp. bin"
So there's some discrepancy (36,707) between these. Please tell me what I am doing wrong, or any thoughts on this would be very much appreciated!