Yes, it did crash. That's how we learned we had to IPL every night. It crashed quite a bit until IBM suggested we an IPL process to our nightly processing.
I see.
What's your point?
Ahh yes. That's why this article is entitled 'Why Mainframes *RARELY* Crash' instead of 'Why Mainframes *NEVER* Crash'
http://os390-mvs.hypermart.net/mvscrash.htm
That's why it says 'These systems, like PCs, do fail,'
Even IBM doesn't claim that it can't crash. So why should anyone believe your assertions when even IBM doesn't claim that.