Indeed, disk transfer speed mattered a great deal in the early days. People used to save all their data to floppy disks, and use their hard disks only to load programs.
Say you had a large document of 600 KB size. Floppy drives wrote at 45 KB/second. Imagine waiting 13 seconds for your file to save out. You might save less often -- which means that you ran a correspondingly higher risk of losing data.
The .DOC file is a binary format so that it could contain document "sections," with pointers between the sections. This is what made "Fast Save" possible. If you only made a small change to an enormous document, Word would simply append the changes, and then change the pointers in the rest of the document.
Instead of waiting 13 seconds, you'd get the save in under a second.
Say you had a large document of 600 KB size. Floppy drives wrote at 45 KB/second. Imagine waiting 13 seconds for your file to save out. You might save less often -- which means that you ran a correspondingly higher risk of losing data.
The .DOC file is a binary format so that it could contain document "sections," with pointers between the sections. This is what made "Fast Save" possible. If you only made a small change to an enormous document, Word would simply append the changes, and then change the pointers in the rest of the document.
Instead of waiting 13 seconds, you'd get the save in under a second.