The detailed, loving description of the baroque boot process takes me back to my days, shortly after that period, of cracking and making "boot only" floppies that either wouldn't show files if read normally, or showed different files; while having something else happen if you booted from it.<p><i>Twitch</i> and <i>shudder</i><p>"Pinball Construction Kit" was a commercial game that used their own floppy format.
What's interesting about this is I feel I could write DOS from scratch with little effort these days. But it would have no value today.<p>The software I write today is <i>far</i> more complex than what was available in the early 80's.
For a minute I thought it was PC DOS 1.1 rewritten in the Scratch language, and I was ready to be impressed. Still a good article. I actually used DOS 1.1, when it came out. I'm old.
> The extra bytes in IBM’s file are mostly zeros, but there’s also a hundred bytes or so of what appears to be junk, more or less random data copied from a buffer that hadn’t been zeroed.<p>Decades-old junk accidentally pulled from uninitialized RAM, saved to disk and now immortalized? That's curiously poetic, if true.
Apropos of nothing, I had a friend who always pronounced DOS like the Spanish for "two" (like DOHS). Most everyone else I ever met pronounced it like "DAWHS". One day this friend meets my boss at dinner. My boss, though a nice guy, was pretty strictly conservative about certain things. Apparently the pronunciation of "DOS" was one of those things. They went back and forth with "DOHS" / "DAWHS" for a while. When I left the table they were still at it. I stayed at the bar for a half hour 'cause I didn't want to know how long that was going to go on.