https://www.pcs-electronics.com/shop/rf ... processor/
and here is the manual (1/2010 is the first release):
http://www.pcs-electronics.com/software ... 25p_en.pdf
Please report any errors or typos you find.
Here's a program to control this unit remotely with a PC (RS232 or USB):
http://www.pcs-electronics.com/software ... rMax10.exe
and the pic:

Release firmware version is:
MP4K+, v1.2, 01/10 (January 2010)
You can check this in your LCD menu system (Firmware)
Latest firmware is v1.6 (09/10)
Please report any bugs you find.
History:
1.3 - Apply LCD contrast immediately after power up.
1.4 - W replaced with K when external power more than 999W
1.5 - fix for settings getting lost after power off
1.6 - longer delay at changing frequency and start-up to allow PLL to lock fully