10 mb is huge for that time. The OS would have been like, what, 800 kilobytes? So after formatting and stuff, I'd figure you had 9.5 megs free.

Install DOS to hardrive, you have crazy fast boot times (probably 15 seconds instead of a minute), and still like 8.8 megabytes for all your text files.

I started computing in 1995ish with a 300ish meg hardrive (I think 320). It was reasonably sized until like 1999.