pkzip also wouldn't create the split archives on your hard drive. It had to actually write to the disks and experience the disk full error for itself. No fun, because you'd have to babysit the whole process, which would take longer than normal due to the compression, without knowing how many disks you'd need. You also had to just hope that none of them would turn out to have errors.

With arj you could tell it you wanted each part to be whatever size would fit on a 1.44 MB DOS disk, leave it going, then do the copy-to-disk step afterwards having been forewarned about how many disks you'd need.