Back in the early 1980s, I came across an IBM XT equipped with a "whopping" 10MB hard drive. The drive alone cost $3000, which at the time amounted to one-tenth the average salary of an electrical engineer. I remember thinking, “Who the hell would need a hard drive that big?” Some people are born futurologists; I'm not one of them.
The XT in question used MS-DOS, but DOS wasn't the first OS to support a hard drive on a PC. That honor belongs to QNX, which in 1982 introduced support for a 5MB Davong. If that sounds small, you're right: it's just enough to store a single photo from one of today’s low-end digital cameras.
Supporting a hard drive wasn’t the only first for QNX. It also became the first realtime OS to support 286 protected mode, to offer distributed processing, and to run on a Compaq 386 machine.
The very first commercial version of QNX required 64K of RAM. That's only six one-hundred thousandths of a gigabyte, a gigabyte being the bare-bones configuration of a modern PC. Still, that was "enough memory to run the OS, a shell, and actually compile programs... it was even possible to do a few background chores at the same time, like printing a file.” I'm quoting from a FAQ written by veteran QNX user Mitchell Schoenbrun.
Speaking of Mr. Schoenbrun, here’s a closeup of him holding a pre-release copy of QNX — version 0.433, to be exact. If you attended the QNX 2000 users’s conference, you would have had the rare pleasure of seeing this ultra-early release running in the QNX booth: