>>>If you look closely at the original IBM PC, you'll see an IBM 370 drastically reduced in size to a few chips and an MS DOS that closely resembles the DOS that shipped with the IBM 370.
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>>I respect you but it astounds me that you consider the original PC a milestone product. It did legitimize the PC market to corporate America, true. But there was nothing revolutionary about it and it was nothing like a 370. If you want to debate IBM mainframes, I'll BXLE that ;-)
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>The revolutionary bit was the open architecture. Just try to remember the other personal computers at the time - the 8 and 16 bit world of then. There weren't any interchangeable parts. The guys couldn't even agree to the floppy size - Schneider was pushing 3", Atari and a few others were on 3.5". Keyboards were integrated. You couldn't use Atari's monitor on an Amiga and vice versa. There were appropriate plugs everywhere, they only agreed on the RS232 (and the short D9 version of it, for the joystick), and later on Centronix. The expressions "video card" and "audio card" didn't even exist, each machine had its own image and sound generators, often incompatible with the previous version of the same machine. Code, and often data, from one manufacturer's machine couldn't run or be opened on another, if you ever managed to transfer them. They even had proprietary filesystems.
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>And since the advent of IBM PC, you could have six machines from different manufacturers, disassemble them, shuffle the parts, assemble at random, and at least four of these would work.
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>If that's not a revolution, I don't know what is.


>>There weren't any interchangeable parts

Exactly.
The "Standard Interface" as it was called then, was a 360/370 concept that carried over to the PC.