DO NOT update anything unless you are trying to solve a problem.
To find the version number:
From the regular loco screen on the cab: Press prog / esc 5 times to get to "Set Cmd Station"
The first thing you see is the command station version that is what we need to know. Hopefully you see 1.65. That is the most recent version.
** IMPORTANT NOTE***
Unless you are using more than two additional NCE devices (not counting the Power Cab), the B patch version is 100% not important.
To purchase a 1.65B chip go here: https://www.ncedcc.com/online-store/Power-Cab-Firmware-Upgrade-Chip-1-65B-p39551974
1.65 and 1.65B - All throttles now have up to 6 recalls
Support for 3 external throttles - addresses 3,4, and 5
Support for 3 additional cab devices such as: AIU, USB, or Mini-Panel using addresses 8,9, and 10
New thumbwheel control of CV programming values
Easy "memory" operation of the last thrown turnout
Support for Analog Fast Clocks
New, improved USB/computer commands
Programmable ‘Pro Cab™ mode’ timeout so multiple Power Cabs™ can be used together
The Power Cab using cab address 2 and anything else using addresses 3 and 4 are UNAFFECTED by the bug in 1.65.
1.65B published in 9/2015 fixes a bug for some users who lose cab addresses 5,8,9,10 after a command station reset. The Power Cab would revert to version 1.28. No additional features or bug fixes are part of this release.