ZTC

Zortech readme document
File type: Various data file
Files with ztc file extension might be found as readme files from old Zortech software.
What is ztc file?
File type category:
Various data file
Date updated: June 28, 2018
The ztc file extension seems to have been in the past used in one of the programs from Zortech, which was a small UK company that marketed C and C++ compilers and associated software until it was acquired in 1991 by Symantec.
Most likely ZTC is very old file type and no longer used.