Sorry, don't know if there is a limit or not.
In the Spring of 1988, I was a medivac pilot in Taegu, Korea. One morning as I entered the office, one of the guys, Dave, hesitantly asked, "AL, you know all about computers don't you?"
I replied, "Well, not 'all' but I do know some. What's up?"
Dave said, "Uh, well, the office computer quit working last night."
I asked, "What were you doing when it quit?"
Dave replied, "I was trying out all the commands in the operators manual."
You are good if you jumped to the same conclusion I did -"Let me guess. It quit working when you reached the commands that started with F. In fact it was Format c:, wasn't it?"
You read about it, but up until then I had never seen it. Literally, Dave's jaw dropped wide open as he exclaimed, "Wow, how did you know that?"
Due to the extra anti-pirating laser holes in the 5.25 floppy disks and other security stuff, it took me two days to convince our 2 thousand dollar copy of db2 that it was okay to reinstall it after I got the DOS back on the freshly formatted, huge 5 MB hard drive. (Yes five mega bytes!)
AL