Trying to re create 2.74b

During the Summer of 2013, I loaded Arduplane 2.74b into my APM 2.5. This being the default available at the time. I was also using the current Mission Planner at the time ( not sure which version ). In November 2013 I wanted to re create 2.74b in a second APM but found the current Mission Planner at that time had a problem with past firmware versions. As a result of a posting in DIYDrones last November, Mission Planner was corrected.

However the 2.74 version that recent Mission Planners now load is 2.74 and not 2.74b. I have tried running a range of Mission Planner versions from last Summer but these also now only show 2.74 not 2.74b

I have looked at and have found several .hex files relating to 2.74b. dated 16th to 19th July 2013. Should I be using the latest of these ?. Can anyone confirm this. Is this where Mission Planner gets it’s files from?

I have downloaded the source for 2.74b from the ardupilot-mega/downloads/list ( dated 15th July ) and even managed to compile it on Arduino IDE on one occasion (although I now get Arduino.h and other .h errors). I did however save the .hex file from this but has a size of 665 kb .The files in are all about 570 kb.

I am keen to re create 2.74b as after hundreds of flights have found it reliable and want to use a known program in a second bixler.

Its this hex … lane-2.74b

Hope that helps.

Hi billbonney, Thank you for your reply. That makes a lot of sense. That entry being the first ( original ) version in the list of 2.74bs. It is also dated 16th July , the day after the date of the 2.74b source code. I mistakenly thought the last entry would be the correct one to use but I guess the subsequent entries are tweaks.

Now looking forward to my second Bixler2 / APM with 2.74b. Now that I can revert back, I may try later firmware variants one day but one of the rule leading to my hundreds of successful flights is to only change one thing at a time!