This article is from the Apple II Csa2 FAQ, by Jeff Hurlburt with numerous contributions by others.
Yes. Many old games and other interesting wares downloaded from "emulator" sites like Asimov will arrive as .gz files. These will, almost always, be compressed 5.25" disk image (DSK) files. They should be un-compressed on the PC via WinZIP before being sent to your Apple II. This avoids a messy de- compression process on the Apple and makes the DSK file available on the PC (or Mac) should you wish to use it with AppleWin or some other A2 emulator program. Note: If you are running an FTP program under plain DOS or Windows 3.x, long file names will be truncated to fit PC's old "8 and 3" format. A .gz file may not show up in your C:\UPDOWN (or whatever) directory with the ".gz" suffix. It is still a .gz file and will not be useful as a disk image (DSK) file until it is uncompressed. The usual size of a 5.25" disk image file is about 143kB. Other chores you will want to handle on the PC before sending a file to your Apple II include converting .HTM (HTML) files to text and splitting up very large Text files. Similarly, it will be easier to view, process, and convert most large graphics files on the PC. ----------------------------