Memory Lane...

I remember this ad, which ran in one of the computer hobbyist magazines in the late '70s (probably Byte).  I remember thinking how amazingly inexpensive that system was.  Just a couple of years prior, I had purchased a used, broken Memorex 630 for $10,000.  I spent a month or so troubleshooting and fixing that thing, and ended up with a washing-machine sized 10 MB hard disk (5MB fixed, 5MB removable).  I had to build a computer to interface with it.

And IMSAI was selling a complete system with a miniature “Winchester” hard disk for just $6,000.  Cheap!

Modern Memory Architectures...

Here's a well-done, accessible tutorial on modern computer memory architectures.  The great majority of programmers today have no idea of the complexity of today's computer memory (RAM, I'm talking about) systems.  When you get to virtual memory systems and the subtle effects of various multi-processor schemes, it's an even larger majority...