OS Stories
The mythology of the IBM PC's operating system has it that the company approached Digital Research (DR), creator of the CP/M OS, but found it lacking in enthusiasm for the project. Microsoft's Bill Gates got wind of this and pitched MS-DOS instead.
In fact, it's likely IBM selected CP/M-86 but was forced to look, at least temporarily, elsewhere as DR's effort to port CP/M to the Intel 8086/8088 CPU was taking longer than planned. Gates may well have pitched an alternative - IBM was already talking to Microsoft about using the latter's implementation of the Basic programming language - and appears to have won the deal in November 1980.
Not long after, Microsoft licensed 86-DOS from Seattle Computer Products (SCP), specifically to sub-license the OS to IBM in turn. 86-DOS had been created by SCP as a stand-in for CP/M-86 and was thus intentionally compatible with the DR OS.
IBM agreed to use 86-DOS, which in July 1981 was acquired in its entirety by Microsoft and renamed MS-DOS. IBM would bundle it as PC-DOS.

Not just for grown-ups
At launch, IBM said it would offer CP/M-86 for the 5150. "IBM has contracted with Digital Research... to make CP/M-86... available for the IBM Personal Computer," the company said on the 5150's day of launch. "We expect [its] availability will provide the opportunity for many current applications to be transferred to the IBM Personal Computer with minimal modifications."
Next page: Send in the clones
COMMENTS
I remember
The polytechnic I worked at took a decision in 1982 to install several computing lab's full of 5150's. Over the summer, we were inundated with the things, with boxes filling all the foyers, waiting to be unpacked. Horrible, horrible long persistence phosphor in the monochrome monitors, and the Poly' decided to ditch the one good feature (the keyboard) for a soft-touch silent Cherry keyboard as standard. Ugh.
I never liked them even then. Because they were floppy-disk only systems, the students had to book out the disks from a librarian for the software before they could use them, which meant that we had fragile 5-1/4 floppies moving around like crazy. We got an agreement through the distributor to allow us to keep the originals safe, and issue copies. Was not long before most of the students twigged on that they could further copy the disks, and then not bother with using the booking system.
I was glad when the first PC-ATs were installed, because we at least then only had to worry about keeping the hard disk clean, and repair the applications when the students trashed them. Introducing a virus on one of the ATs became one of the most serious offences, and we had to have disinfectant sessions to clean the student's own floppies to protect our systems and their work. Mind you, the 1.2MB floppy drives on the ATs caused no end of problems when students tried to write to 360KB floppies on them.
This was waaaaaay before disk cloning was thought about, and everything was done according to the installation process, although one of the labs (not one I worked with) was set up with a low cost (hmmm, relatively low cost, it was still bloody expensive) co-ax CSMA/CD Ethernet alternative called Omninet running at 1Mb/s for file and print sharing.
Interestingly, we had Pick installed on one of the ATs, and Xenix-286 on another.
I still regarded the PC's as poorer teaching tools than the lab of BBC micro's I also ran, and of course 'my' UNIX V7 (and RSX-11M) PDP11/34e (in Systime covers, with 22bit addressing and 2MB of memory, and CDC SMD disks to speed it up) was the bees knees as far as I was concerned, running Ingres to teach relational database. Knocked Ashton Tate DBase II (remember that!) into a cocked hat! And it was, of course, far less maintenance work.
The software line-up on the PCs was PC-Dos 1.1 (on the 5150s, the 5157's has PC-Dos 2.1 for the hard disk support) with Word 2, Multiplan (MS spreadsheet before Excel), and DBase II. I couldn't work with Word then, and still find it a traumatic experience now.
We definitely need either a rose-tinted spectacles or an old-fart icon here. I guess I'll just have to use the coat icon. It's the one with the big stretched pockets to hold the 5-1/4 disk box.
keyboards
things may have moved on but nobody makes keyboards as good as the ones that came with the original '81 IBM PC!
Still in use in 1998
In the late 90s my mother volunteered at the local church doing admin work, and they were still using a model very similar to one of these! I don't think it was a 5150 because it had a 30MB hard disk, although I suppose that could have been added later. I was fascinated by this living antique and used to go in on my days off from college to play around with it.
It ran a very early DOS and a green-screen, keyboard-operated version of MS Works (or some equivalent, I forget), comprising a simple word processor and a spreadsheet program. There was a similar epson dot-matrix printer attached too. It booted in about 5 seconds and was ready to use.
The best part was, IT DID ABSOLUTELY EVERYTHING THEY NEEDED.
Sometimes, I'm not sure how much progress we have really made!
as crap as they were, retrospectively
The whole early steps of computers and associated technology seemed a lot more inventive and interesting than it does now.
Title
Anyone else remember the PC dept doing "compatibility testing" of non-IBM PCs by running MS Flight Simulator?
Well that's what they told us it was for, anyway!

