I didn't find it particularly confusing. I feel as though most people would take "midrange computer" to be what the author intended. Might just be projecting my own ignorance of the IBM systems however.
The term "midrange computer" to me is more synonymous with "minicomputer" (ala AS/400, etc.) than it is with "desktop tower PC" or whatever. My guess would be that most people would interpret it the same way, given that "midrange systems" is a pretty established and well known term:
That's what I thought he meant as mid-range in terms of price/performance is always relative and changing. Maybe I should've known better.
> most people would interpret it the same way
For most people, a computer is PC.
That was my immediate thought too, and I half expected to see 20 year old article. First thing I looked at was the date and I thought, "I wonder what this guy is writing about".