pete@octopus.UUCP (Pete Holzmann) (08/10/87)
If I'm not mistaken, there's one major additional reason why the first
PC's were based on the Intel architecture... and I think it probably holds
more weight than the CP/M compatibility issue:
The 8087 math coprocessor was reasonably unique at the time. Nobody
else had anything close. And (unfortunately) the 8087 doesn't work
in non-Intel-chip environments.
From my experience with consulting for IBM, I'd say that CP/M compatibility
was almost certainly a non-issue for them: they design stuff without ever
looking at the 'real world'! If you remember, DOS was only one choice at
the time... the P-system (very un-CP/M-ish) was actually more popular to
begin with!
So leave all the 808x compatibility arguments alone. IBM wanted to design a
PC in an IBM-kind-of-way, and that's what they got. MicroSoft (and Seattle
Computer Systems) just picked an easy solution to the problem of providing
an O/S for what IBM ended up with.
What is the 'IBM-kind-of-way'? As far as I can tell (I think I heard this
from an official source once) it is:
- Make a GOOD product (no need to push the limits, in general)
- At an ACCEPTABLE price (amazing what corporate America accepts!)
- And make BIG PROFITS
IBM is *VERY* good at making BIG PROFITS. If you look at what they
do in light of these goals, things tend to make more sense. They
tend to cut prices only if the profits are threatened sufficiently
by other companies' market share gains, etc. etc. etc...
Enuf for now!
--
OOO __| ___ Peter Holzmann, Octopus Enterprises
OOOOOOO___/ _______ USPS: 19611 La Mar Court, Cupertino, CA 95014
OOOOO \___/ UUCP: {hplabs!hpdsd,pyramid}!octopus!pete
___| \_____ Phone: 408/996-7746Isaac_K_Rabinovitch@cup.portal.com (08/13/87)
pete@octopus.uucp says:
>(a bunch of reasons why IBM was never interested in CP/M compatibility)
Actually, IBM offered *three* OSs with the first PCs, including CP/M. But
MS-DOS was half the price of the other two. What clinched it for MS-DOS
was all those applications developers writing for it.
I get the impression that IBM didn't even think about system software when
they were planning the PC. Legend has it that they didn't start looking
until a few months before release, that Digital Research didn't return their
calls, and that Bill Gates didn't even buy Seattle DOS (which was then just
a CP/M clone) until after he'd promised IBM an OS.
IBM is like the proverberial Grizzly Bear. Grandpa, why is there Grizzly
Bear sleeping on your front porch. Son, you ask it, I'm not gonna.johnl@ima.ISC.COM (John R. Levine) (08/14/87)
In article <595@cup.portal.com> Isaac_K_Rabinovitch@cup.portal.com writes: >pete@octopus.uucp says: >>(a bunch of reasons why IBM was never interested in CP/M compatibility) >Actually, IBM offered *three* OSs with the first PCs, including CP/M. But >MS-DOS was half the price of the other two. What clinched it for MS-DOS >was all those applications developers writing for it. I've always heard that the plan for the PC included a Z80 processor until late in the design process. Then IBM realized that a better processor would distinguish them from the other zillion mediocre CP/M boxes out there. Only Intel had a part, the 8088, that they could plug into their 8-bit designs without having to completely redo all of the peripherals for a 16-bit bus. The 68008 was nowhere near ready in 1980. Rumor also has it that IBM was under the impression that MS-DOS was fully compatible with CP/M-80 until somewhat after the PC was shipped. I can see the conversation now: IBM: Is this system you're offering us 100% compatible with CP/M on the Z80? Bill Gates: It doesn't make sense to ask, since the 8088 isn't binary compatible with the Z80. IBM: Our marketing surveys tell us that any system we sell has to be 100% CP/M compatible to sell well. Gates: Then why are you using an 8088 which won't run Z80 code? IBM: Our marketing surveys tell us that a more powerful processor will gain us market share. Gates: But no 8088 operating system can be 100% Z80 compatible. IBM: Well, we can't sign a contract to buy 500,000 copies of your operating system unless it's 100% CP/M compatible. Gates [no fool]: Oh, in that case, it's 100% CP/M compatible. -- John R. Levine, Cambridge MA, +1 617 492 3869 { ihnp4 | decvax | cbosgd | harvard | yale }!ima!johnl, Levine@YALE.something The Iran-Contra affair: None of this would have happened if Ronald Reagan were still alive.