June 19, 2019:
SCS Tracker DSP packet radio TNC firmware version 1.7F is now available for download from the Files section of the Robust Packet Yahoo Group or via the the beta firmware option in the SCSupdate program.
UPDATE: Firmware version 1.7m is the latest firmware as of October 2019.
Per SCS an easily overlooked source code formatting error snuck into a subroutine portion of the code in a way that didn’t throw any errors when compiled. This impacted the HDLC state machine’s ability to properly track multiple incoming frames. This is the bug detailed in some of my recent RP Group postings.
While this should be considered “beta” firmware for now, it appears to have solved the above problem. If you use your Tracker DSP TNC for VHF/UHF packet then you should strongly consider installing this free firmware update.
NOTE: I have SCS looking into another packet mode bug that is on the transmission side of things. The TNC will never send more than 2 frames regardless of MAXFRAME settings. This may be a Winlink Express bug and more testing is needed. This would generally only impact 9600 baud users with degraded upload speeds.
UPDATE: Appears to be a Winlink Express bug with the DSP Tracker in 9600 baud mode. Bug report filed February 26, 2019 on the Winlink Programs Group.
Do note that RPR is hard coded to limit maxframe to 2 by design. Thus this issue does not impact RP mode.
My thanks to John KX4O of VAPN for his help and testing.
Thanks to SCS for their excellent ongoing support and desire to further improve the Tracker DSP TNC for both ARPS and non-APRS uses.