At the time, storage was still a couple hundred dollars per gigabyte - and that's if you stored only a single instance (no redundancy) and owned the drive. Clus

At the time, storage was still a couple hundred dollars per gigabyte - and that's if you stored only a single instance (no redundancy) and owned the drive. Cluster that up a bit on machines you're renting and allow for backup writing time, and things start to add up. Those costs multiply out pretty quickly as you step back in time - head back to the '80s and you're talking hundreds of thousands, not just hundreds. Saving a couple of bytes here and there made a huge difference - and windowing as a Y2K mitigation could be enormously cheaper than rewriting large chunks of large applications that were built around costs we can barely comprehend, let alone remember dealing with these days. (I speak for myself and my own failing memory here.)