The files on the
z80.de site may be zipped, needing unzip on Windows, then transfer to rc2014, or using a new unzip from github , courtesy of Tony Nicholson. Search retro-comp Google group for details.
The file packager on rc2014 is for a more modern simple format, originating from Grant Searle, to pack and unpack files, and maybe to use his and subsequent
download.com. search Google to find grant searle's site.
More compression formats exist eg arc, ark, arj, lbr (using nulu, lu etc). These can be extracted under cp/m.
Again use Google.
Lots to learn. Please do investigate further to improve your background knowledge. Many questions can be avoided by using Google first. Unfortunately for non English users, the Google info is mostly in English, but Google translate can work quite well, but not perfect.
Happy Retro computing
Cheers
Richard