*.BCK files are VMS BACKUP savesets; *.ACS files are the same savesets, compressed, ASCIIfied and packaged in a self-unpacking format (requires only MACRO, LINK) If you have MultiNet, or if your TCP/IP's FTP supports STRUCTURE VMS, you can transfer the *.BCK version of a saveset. If your FTP doesn't do STRUCTURE VMS (or if you want to transfer a shorter file, but then spend local CPU cycles decoding it), transfer the *.ACS version, which is an ASCII text file. Please conserve bandwidth -- transfer one or the other, not both! (See AAAREADME.INDEX for a brief summary of directory contents.)