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How the IBM PC Changed the World
Sabah Arif writes "On August 12, 1981, IBM released the IBM PC 5150. In less than two years, IBM had created a computer that would not only change IBM, but the entire world, mostly because it did not follow IBM tradition. It used an outside microprocessor (instead of the nascent IBM 801), operating system and software. Low End Mac recounts the birth of the IBM PC 5150."
These days, no turbo button, so I'm stuck at a crawling 3GHz...
I don't know why it is considered so great historically. CPM machines had spreadsheets and dBASE and word-processors and were doing quite well. The IBM PC stole that market and killed CPM because of the brand name. CPM would have been the base framework of the machines we use today had it not been for the IBM PC. In fact, the PC barrowed CPM-machine hardware in many cases.
Table-ized A.I.
Was the 'blue box' Altair.
It inspired most of the techno-nerds from Gates to Jobs.
On the one hand, the x86 is a terrible design. It doesn't have enough registers, and the assembly interface is awkward (especially in the FPU). On the other hand, the openness of the architecture has freed us from the shackles of dependency on a single company for hardware (which DRM would like to lay back on us). If you don't like Intel, you can go to AMD. There are tons of board manufacturers to choose from, and all the parts need to be (more or less) interoperable.
This prevents one manufacturer from imposing their wishes on us. If Microsoft had control of their personal computer platform the way apple does, we surely would have lost the battle to DRM already. Computers would be more expensive because there wouldn't be competition from cheap manufacturers in Taiwan to drive the prices down.
The x86 may be an ugly beast, but it gives us the freedom that only openness can bring. And I will drink to that.
Qxe4
The article gave pretty short shrift to the Compaq engineers for the reverse engineering of the PC architecture.
Imagine you were Chinese and had laid bare before you the innards of some cool technology that until now was locked up tight. You'd be the first one to put down your eggroll and cat-kabob and get right to the task of extracting its secrets. That's when you'd open up the clone market. It wouldn't be the prerogative of the original company whether you created the clone or not, it's out of their hands once they decided to use an open architecture.
Compaq blazed the clone trail, not IBM.
Sadly I couldn't get it too, wouldn't fit on a 5" floppy.
Just after the PC introduction (at NCC fall 1981) I told my father-in-law that we should re-implement the software used for OCR processing in his downtown office. We should select something PC-compatible since this new open architecture was bound to generate compatibles, thereby ensuring a pretty long lifetime.
:-)
After looking around the market, we bought two Columbia PCs, one desktop (with an immense, never to be filled, 10 MB hard drive) and one luggable, for the same price as a single IBM PC.
The Columbia machine came with a BIOS/HW manual that documented all the various lowlevel interfaces, including the port adresses for things like the serial port and the interrupt controller, which allowed me to write a hw interrupt driver for the incoming 9600 baud OCR data stream.
Columbia was both earlier than Compaq and more compatible, but that didn't matter, they still went under a couple of years later. The PCs lived for many years however.
Terje
"almost all programming can be viewed as an exercise in caching"
"Probably"? :-) When I was in college, Apples were 'it' for the in-school computers -- IBM hadn't developed the 'PC' yet. We still had terminals and modems for accessing the CDC mainframe, but the Apples were there, and they were all yours. No sharing, no operators, just pop in your disc and go. It was an amazing machine.
I wanted to get one for home, but my dad told me we weren't going to buy an Apple. He was waiting for the IBM home computer to come out. He said "IBM doesn't do anything half-assed. If there's a business need for it, IBM will come along and completely dominate the market. Apple will be pushed aside; they'll never make it as the mainstream computer for businesses."
I, of course, couldn't believe that for a second. Every school in the state had Apples, they were everywhere, and this IBM thing didn't even exist! How could he even think that a company with no experience in home computers would take over the market, especially since Apple was so well entrenched?
Y'know, I wish I'd listened to my dad more. He was a very, very wise man.
John
1. The IBM PC was initially sold for about $1295. That was much cheaper than any other IBM computer. Apple and Commodore had cheaper computers, but small-business owners want the IBM name on their computers. Business people tended to view Apple computers and Commodore computers as toys.
2. The computer had the IBM label on it. These days, the IBM label does not carry the same cachet that the IBM name carried in the 1980s. At that time, IBM dominated the mindshare in the computer industry. People often said, "No one was ever fired for buying an IBM computer."
3. IBM encouraged other companies to build hardware and software for the IBM PC. It literally came with a full set of manuals documenting the entire BIOS and the internal wiring among the chips of the motherboard. Compare that open approach to, say, the typical Sony laptop. The plethora of software and hardware peripherals for the IBM PC enabled it to be adapted to a wide-range of useful applications: music synthesis, video games, desktop publishing, real-time intruder monitoring, etc.
4. Phoenix Technologies cloned the BIOS, enabling an army of companies to legally build functioning clones of the IBM PC. This army of cloners then spawned an entire universe of component suppliers. This intense competition among so many cloners and suppliers drastically lowered the price of the IBM PC and its clones. In turn, the lowered prices dramatically increased sales of the personal computers. Today, you can buy a Dell laptop for $500.
As prices dropped, more people bought computers; with more people owning computers, more companies building software and hardware for the computers appeared. Lather. Rinse. Repeat.
Among the four factors, item #4 is probably the most important factor in amplifying the impact of the IBM PC on the entire computer industry.
You can easily see the impact of #4 by comparing (1) the size of the ecosystem of companies building hardware and software for IBM PCs (now known as Lenovo PCs) and their clones and (2) the size of the ecosystem of companies building hardware and software for 68000 Macintoshes or PowerPC Macintoshes. Still more interesting, the enormous size and supercompetitive nature of the 1st ecosystem has swallowed even Apple: the new x86 Macintoshes are essentially (in a very general sense) an IBM clone. The x86 Macintoshes use the x86 (the central component of an IBM clone) and take advantage of the super-cheap VLSI chips from which IBM clones are built.
I retired a 5150 in 1995. It had a hard drive and maybe 128k. We used it every day. It was the computer we all used to store our CNC programs on. Connected to a serial port switch box running 100's of feet of cable to the CNC machines. It worked until the day we turned it off and replaced it with a contemporary Pentium. That was the last time I saw a 5150 in working order.
What the IBM 5100 really represents, in retrospect, is the beginning of the turnaround for IBM in the minds of the public. It's difficult to think of another example of a company so large and so universally despised eventually becoming the (mostly) developer friendly company it is today.
By allowing their teams to skirt the system occasionally, we've seen truly open hardware (PowerPC) availablity, open source contributions, free training seminars for developers, etc. The 5100 was the first great example of the success that a little rule-breaking can bring to the company.
IMO, it was exactly that product and the example that it was to IBM internally that allowed IBM to do the one thing no one was entirely sure it would be able to do in the age of personal computers -- survive.
My hat's off to the improvements IBM has made in the last 25 years, and I hope that those lessons won't be forgotten over the next 25 years.
His conclusion was right but his premises were false. Apple made computers as well as or better than IBM. They just weren't as prescient on the business side. They failed to get a clue once they introduced the Macintosh, when it was time for both sides to lay down their chips. Microsoft, with Windows. Apple with the Macintosh Operating System. If Apple had chosen at that point to license its operating system we would be in a very different world today. I'm not sure that I would prefer that world, because chances are Apple would have become anti-competitive and monopolistic, and their product quality would have diminished. And Microsoft wouldn't have likely risen to be the resident industry source for R&D innovation like Apple has done in actuality.
In a way, they continue to make the same mistakes - only this time, they're not mistakes. They are still controlling every aspect of the platform. However, they are positioning themselves in such a way that will result in a much higher-profile competition with Microsoft - a head to head battle, the same hardware platform with different software. If Apple ever overtakes Microsoft in market share (in the distant future, if at all) they are then in a position to start licensing their operating system, and they will have recreated the opportunity they completely missed in 1984.
In the IBM Site http://www-03.ibm.com/ibm/history/exhibits/pc25/pc 25_intro.html reffers that IBM PC 5150 was released on September 1981.
In fact all the early processors had their architectural horrors. The 9900 had an absurd system in which the bit order of IO was reverse numbered with respect to the bus and we actually got an I/O board into production before we realised this owing to the poor documentation. The 68000 constantly caught out assembly programmers because of its word alignment issues, resulting in one occasion in a programmer going near berserk and having a screaming fit in the lab, fortunately when the boss was out at a meeting. And don't talk to me about the F100/L except to say that Ferranti did not get as much pain as they deserved for creating it. Not that it would ever have become mainstream...
It's easy to be clever with hindsight, but the Power architecture came later and too late. After, as I recall, the NS32032 which, despite some performance issues, was a processor I really liked.
Pining for the fjords
For the record, all the popular small systems of the time had third party add-ons. That's a tradition that goes back all the way to the Altair. The Apple II didn't even have an RF modulator, because a third-party deal saved some headaches for Apple. All the systems came with full documentation. Apple even gave you the source code for the whole ROM in a separate manual right in the box, along with the schematics. Cloning the BIOS happened long after the PC had established its place - and the first clones had significant compatibility problems. Clones really didn't take off until Compac beat IBM to market with a 386-based machine.
Man, the hardware... Hewn from a single piece of purest iron those things were (literally?) bullet-proof. The keyboards would last for years before even one of those keys stopped working.
Of course, you couldn't lift them. But whilst machines now whirr away at insane speeds and generally work well their keyboards suck.
Er... that's it. Just got misty-eyed there for a second.
Smokey, this is not 'Nam, this is bowling. There are rules.
Funny you should mention it. I was just reading this fascinating account by Steve Wozniak about how he invented the Apple I (semi-technical), and he talks a bit about the Altair.
//gs?
Anyone have a "Woz"
W
-------------------
This is my SIG. There are many like it, but this one is mine.
Actually, had PC clones not emerged, Microsoft would have been relegated to the scrapheap of history as just another vendor of a BASIC interpreter. And a fairly crappy BASIC at that.
However, once the clones emerged, MS had it made. IBM was certainly not prepared to put in the engineering work to make PC-DOS run on non-IBM hardware. Microsoft, however, was willing to do that work (or at least let PC OEMs pay Microsoft to teach them how to do it themselves), and offer pack-in deals. As such, IBM PCs came bundled with PC-DOS, and every other machine came bundled with MS-DOS.
Back then, just about everyone in the engineering community knew MS-DOS was shit, and would steer anyone who would listen toward PC-DOS, or Digital Research's CP/M-86 or Concurrent CP/M. However, most end-users considered MS-DOS to be "good enough," and it was "free," and they wanted to be able to run the same software they used on the real IBM PC at work on their cheap(er) clone at home. And besides any bugs were the application's fault.
Oh, and you're also forgetting what the gold standard of PC compatibility was at the time:
Microsoft Flight Simulator.
Amazing foresight? Maybe, to some degree. But in large measure Gates fell flat on his face into a pile of amazingly good luck.
Schwab
Editor, A1-AAA AmeriCaptions
There is more on the BBC website, http://news.bbc.co.uk/1/hi/technology/4780963.stm with some nice old adverts for the PC. http://news.bbc.co.uk/1/shared/spl/hi/pop_ups/06/t echnology_ibm_pc_anniversary/html/1.stm
This is why I use an IBM keyboard which is over 10 years old on my present machine. The short of it is if the computer will not run this keyboard then I won't buy it or use it.
Well, in those days other chip manufacturers used a single interrupt line and either polling or vectoring. Priority was determined by the software or by a hardware daisy chain (e.g. in Zilog's vectoring system, which worked beautifully).
Intel used a special chip that was dedicated to interrupt vectoring, the 8259. It had 8 inputs of fixed priority, int 0 being the highest and int 7 being lowest.
The 5150 had one of these, and the ints 0 to 7 were partly hardwired and partly on the ISA bus.
A stupid design mistake was made: interrupts were edge-triggered on the 0->1 edge of the input. This was a programmable option in the 8259, which could also operate in a level-sensitive mode. This mistake meant that interrupt lines could not be shared between cards.
(other manufacturers of the time used active-low level-sensitive mode, which meant it was possible to share interrupt lines)
When the AT appeared, and the number of available lines was felt too limited, a second 8259 was connected to int 2 of the first, and its input were designated 8..15.
Input 9 was connected to the bus pin that originally was number 2. Hence the 2/9.
The priorities of inputs 8..15 became relative to int 2, thus the complete priority sequence becomes:
0,1,[8,2/9,10,11,12,13,14,15],3,4,5,6,7
Some of those (0,1,8,13,14) are used on the motherboard. The remainder is on the ISA bus.
Later, when MCA and PCI were developed, engineers corrected their mistake and used level-sensitive interrupts that could be shared.
But in the name of backward compatability, the strange interrupt numbering and handling has always remained there.
(current systems have 24 levels and more freedom in programming the whole thing to the OS developer's liking)
The fuss was about a computer that could be used in a business, vs the hobby computers that were popular before that.
Most of the hobby computers could not stand up to professional daily use, and the IBM PC could.
Personal computing went from hobby computing to being a business tool.
We're spoiled. I remember a friend enthusing that his firm had just fitted Maths CoPros to their XTs (I think) and that they could now refresh big AutoCad drawings in mere minutes.
I want a list of atrocities done in your name - Recoil
Did you ever wonder why ALL XT/AT motherboards in standard form factors had two power supply connectors? Especially since they were not keyed? (swapping the two could easily blow your motherboard.) I have heard that when IBM was preparing to ship the 5150, the supplier of power supply connectors (it happened to be Molex at the time) was out of stock of the 12? pin connectors necessary to integrate the whole PS connection into one. After that, every single PC Power Supply for many years shipped with two connectors on the output, because it had always been done that way.
Probably a crazy urban geek legend, but a cute story nonetheless.
SirWired
Restrictions are designed to increase the profitability of the vendor and therefore always increase the costs to customers. Inevitably at some point a more open and lower cost alternative always appears. If IBM hadn't released the specs, something else would have appeared which we'd be using now. It's economically inevitable. This is actually why Linux will ultimately replace Windows and most other operating systems.
Deleted
While it's true that Microsoft Flight Simulator (NOT Sublogic) was the compatability standard mentioned in every review, the thing that sold all those PCs and all those copies of PC/MS-DOS was Lotus 123. 123 made the PC the way VisiCalc made the Apple II. Because Lotus wrote directly to the video memory, "sorta" clones (DEC Rainbow anyone?) that had BIOS, but not physical compatability, had no chance.
No folly is more costly than the folly of intolerant idealism. - Winston Churchill
The 68000 didn't have fixed opcode size. The minimum was 2 bytes though. If you think 2 kinds of registers are a nuisance you should try programming on the x86!
Later 680x0 processors allowed you to use Dx registers as address registeres IIRC, but had a performance hit.
Everytime I see this I have to shake my head... I had my first "desktop" in 1978. Ok it was not much.. A Radio Shack TRS-80 16K LevelII. sporting an 8088 blazing at 4mhz, a tape drive(cassettes). Heck it even had voice recognization(worked ok, bout as good as todays stuff). I still have this machine and it works just fine.... There where also many a Heathkits out there to in those days... IMO statements such as this article makes "about IBM changeing the world" will are just plain false....
First of all the 68000 cpu was not yet available when IBM started
to design the PC. In fact, they were going to use an 8085 cpu, which
they were using in their DataMaster series of machines. The PC ended
up with the same bus already used in the DataMaster. IBM switched to
the newly released 8088 at the suggestion of Bill Gates.
The very first deliveries of 68000 cpus were locked up in advance sales
to General Motors for use in auto electronics (smog control computers).
Until Motorola could ramp up production very limited numbers of 68k chips
were sold to anybody else.
The 68000 IS a 32 bit machine in the sense that it has 32 bit registers,
and a 32 bit instruction set. It is constructed with 16 bit data paths
and a 16 bit alu however. The 68020 is a true 32 bit machine with 32 bit
data paths and a 32 bit alu. The 68020 can run the same software as the
68000 (it is actually binary compatible with the 68000). Motorola intended
from the start to produce a 32 bit microprocessor but could not get the
needed number of transistors on board till later on.
The 68K series were not really a dead end. For a few years Motorola matched
Intel with new processors. The 68030 matching the 486 and the 68040 the Pentium.
Apple's sales were only a small precent of the PC world and Motorola was loosing
interest in the 68K. They started promoting the PowerPC processors with IBM and
for a while it looked like IBM would start shipping machines based on this part.
Apple thought it would be a good idea to jump ship, but the PowerPC processors
never really caught on outside of IBM's mini mainframe business. (Deep Blue of
chess fame was a PowerPC cluster). Now Apple is jumping ship AGAIN, this time
to Intel.
The thing is, POCs weren't successful because they were clones. They were successful because they were IBM clones. Apple had their own OS. So did Commodore, Sinclair and all the others. Even more recently, Sun, SGI and all the big non Wintel companies have used their own OS. Selling the OS as a separate item has always been atypical.
So, Scenario 1: MS manage to convince HP and DEC to licence their OS. This makes two a big assumptions in the first place - That they wouldn't want to make their own systems, and that Microsoft would be the ones who manage to convince them. But even if they do go with Microsoft, why are people going to buy these machines? They're not IBM or Apple. They have no software library. We're also assuming that IBM would do everything in house, even though Apple became successful from third party software (i.e. visicalc). My view is that IBM would make their own system, and it would sell because it was an IBM. All businesses would buy one, and prices would remain high.
It's possible that MS would get to the same position they're in right now by writing Windows, but they'd need some degree of success beforehand, and they would be competing directly with OS2
Meanwhile, the rest of the market would create their own competing incompatible computers. Eventually, a few of these companies would work to come up with a standard. This may use a third party's software. However, even though IBM are keeping prices high, the cost of the home computer would fall - possibly even more - and we'd have a situation similar to the 8-bit era lasting until a standard is formed.
As for Scenario 2 (and I can't imagine MS would object to exclusivity back then): Well, I think things would turn out just the same. IBM would be more likely to succeed. If MS created windows, it would be more likely to be licenced exclusively to IBM.
The tech industry would always have evolved. If someone can make hardware for less, then they will do so.
I had one of these speed demons. I grew up playing on my dad's Apple ][ (not plus) but played a lot of games. So he got me a 5150, fresh off the line. It had cassette ports even! But he splurged and got me the dual floppies. I still have my DOS1.0b diskettes and manual here, along with the other 3 manuals that came with it but sadly, the machine itself is no longer. In a bid to ensure that I wouldn't play games on it, my parents did not buy me the color graphics adapter and monitor. I had the monochrome monitor and adapter. I was a sad, sad boy. I couldn't even understand its assembly language. Sad, Sad boy of 15. Eventually I ended up getting a 300baud acoustic modem, shortly thereafter upgrading to 1200, and eventually ending up with an email address starting at !ihnp4!.... Life became more interesting around then...
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