03/03/2008 Initial Release, Firmware release 1.0
04/15/2008 Removed C23 (adjustment to the 5V rail rise time)
04/15/2008 Firmware 1.1 changed timing scheme as follows:
 
P0  STANDARD PSU  
P1 5sec / 1min            was 5sec 1 min
P2 5sec / NEVER    	  was  5sec / 1 hour
p3 1min / 1min            was  5 sec / NEVER 
p4 15 min / 1 min         was  30 sec / 1 hour
p5 15 min / NEVER         was 30sec / NEVER 
p6 30 min / 1 min         was  30min / NEVER
p7 2 h / 1 NEVER          was  3h / NEVER
 
04/14/2008 Firmware 1.1: 1minute Ignition latch was active only when M4-ATX was powered on for the first time
04/14/2008 Firmware 1.1: Further alignment in the way 12, 5, and 3.3V rails startup timing
04/14/2008 Firmware 1.1: Firmware version can be viewed via USB HID link.
04/14/2008 Firmware 1.1: UPSMode implemented
 
06/06/2008 Firmware 1.2: Introduced +750ms wait time between 5VSB on and ON/OFF pulse,value can be changed by user through USB
 
06/19/2008 Firmware 1.3: Thump OFF timeout starts when rails are started
06/19/2008 Firmware 1.3: Thump is active ON only during the rails are ON
06/19/2008 Firmware 1.3: In modes 1-7 if Ignition is still ON and PC was manually shut down (from OS) M4 won't go to Hardoff state instead it will go to 5V standby and wait for start pulse. 

06/26/2008 Firmware 2.0: New firmware for the modified hardware with temperature sensor on the back of PCB
06/26/2008 Firmware 2.0: Functionality is the same as for version 1.3

10/07/2009 Firmware 2.1: Default value Min VIN voltage at PSU startup changed to 11V
10/07/2009 Firmware 2.1: Default value Min VIN voltage while 5VSB=ON changed to 11.5V
10/07/2009 Firmware 2.1: fixed:Software patch/workaround for i2c temperature sensor hardware hangup problem (occured when VIN is quickly disconnected and reconected),it could hanged up the M4
10/07/2009 Firmware 2.1: fixed:if M4-ATX is connected on USB to a different PC( not that it is powering )and is going to low power mode and it is coming back it won't reconnect on USB.(in P1..P7 modes) only if it is physically disconnected and reconnected

08/01/2010: Per EEC, Fairchild will EOL FDS6680A in 2011, we will switch to FDD8880 in mid-late 2011.

10/06/2010: Removed C7 from BOM, no longer used.
10/06/2010: Changed C64 from 1uF to 2.2uF / 10V or 6.3V 0603 XR5/X7R

10/15/2010: Extended life cycle for another 5 years.