Question:  I've acquired a used Matrix +2 system with panels that works properly, however the PC that was used for programming the system is no longer working and we can't determine which version of Clear-Com Matrix +2 software to download.  How can I determine which version of software to use?
Answer:  There are two possible ways to determine the firmware version of a Matrix +2 frame / panels when the host PC is unavailable. 
1.  If the user has access to a connected panel that has an electronic display readout (ICS-92, ICS-2002) the user can interrogate the panel for the firmware version:
ICS-2002 panel -  press the "Menu" button on the keypad and select Version Information from the display screen, this will show the firmware version on the panel
ICS-92 panel - press and hold for at least 4 seconds the "Listen Labels" button to display the panels firmware version
2.  open the panel to expose the main pcb and look for the socketed 27c256 EPROM, the paper label on the prom should show a version number that corresponds to the software version required.