WarGames and the Great Hacking Scare of 1983

James W writes "Yesterday was the 25th anniversary of the release of WarGames and Christopher Knight has written a retrospective about the film and its impact on popular culture. In addition to discussing how the movie has held up over time, WarGames was responsible for what Knight calls the Great Hacking Scare of 1983. Some examples mentioned are 'one CBS Evening News report at the time that seriously questioned whether parents should allow their children to access the outside world via their personal computers at home. A magazine article suggested that computer modems be 'locked up' just like firearms, to keep them out of the reach of teenagers. I even heard one pundit proclaim that there was no need for regular people to be able to log in to a remote system: that if you need to access your bank account, a friendly teller was just a short drive away. And Bill Gates once declared that the average person would never have a need for more than 640 kilobytes of memory in a personal computer, too.'" 2008 is also 25 years after the real-life prevention of a WarGames-style nuclear incident.

Comments

Ugh...

[FrYGuY101]

No. Bill Gates did not say that.

Stop spreading these myths.

[91degrees]

And Bill Gates once declared that the average person would never have a need for more than 640 kilobytes of memory in a personal computer, too.'"

No. He actually never said that. Not once.

Re:WarGames and Disillusionment

[NullProg]

I was incredibly depressed when the computer exhibited neither near-human emotions nor a synthesized English accent.

Thats because you didn't have S.A.M.
http://en.wikipedia.org/wiki/Software_Automatic_Mouth

Enjoy,

Might as well mention the DEFCON game

[Dr. Manhattan]

By Introversion Software. It's the "Global Thermonuclear War" game from the movie, mostly. Fun, though a little disturbing at times. Runs on Linux and Mac, too. Inexpensive as well.

In fact, I think I'll go home and play some.

Re:Locking up computers

[CogDissident]

He is talking about the mafia (music/recording industry derogatory term) suing them for downloading music/movies.

What's more

[Sycraft-fu]

DOS has absolutely zero to do with that limit. The limit came from the computers themselves, and how they addressed memory. They had a 20-bit address bus which gives you 1MiB of addressable memory. Now being 16-bit devices, that meant that they accessed it in 64k pages. However, as Gates noted, it was divided so you only had 100 pages that could be used for regular programs. The rest was reserved for hardware. Hence the 640k limit.

You can actually see a similar (though not the same thing) situation today when you approach 4GB of RAM in a 32-bit system. With a 32-bit address bus you can, of course, address 4GB. The problem is that hardware still needs memory areas to work, and actually far more than it used to. So you'll find that you get less than 4GB of RAM accessible, how much depends on what hardware you have installed. To actually get full use of the 4GB of RAM, you'll need to run on a 64-bit chip, which has a larger address bus and thus memory ranges for the hardware.

So DOS was never the reason here. It was the way the hardware was designed.

Re:What's more

[Lally Singh]

Uh, no.

First, 64k/page * 100 pages is 6400k.

Second, the 640k limit was due to the video ram being mapped in the memory region between 640k and 1 MB, at address A000:0000. Which is why DOS extenders could get you that memory back in 386+, by remapping the memory to other addresses. Here's a memory map: http://www.infokomp.no/techinfo/doc/DosMemory.htm

Third, your 32bit/4GB ram stuff is garbage as well. Most OSs claim address space at the end (the upper 1/2GB) for the kernel. That makes it harder to use. It's not a hardware problem at all, OSs tend to have simplistic userland/kernel memory address space mappings. CPUs went to 64 bit before 4GB was cheap enough for this to be a problem, so no work was done to really reduce the kernel address space footprint (or to separate the address spaces altogether).

Re:What's more

[Lemming Mark]

Uh, no. First, 64k/page * 100 pages is 6400k.

Actually, I recall x86's real mode pages actually overlapped in the bus address ranges that they mapped to. So in this case number of pages * page size doesn't give total addressable real memory. Can't remember the actual numbers, however.

Second, the 640k limit was due to the video ram being mapped in the memory region between 640k and 1 MB, at address A000:0000. Which is why DOS extenders could get you that memory back in 386+, by remapping the memory to other addresses. Here's a memory map: http://www.infokomp.no/techinfo/doc/DosMemory.htm Third, your 32bit/4GB ram stuff is garbage as well. Most OSs claim address space at the end (the upper 1/2GB) for the kernel. That makes it harder to use. It's not a hardware problem at all, OSs tend to have simplistic userland/kernel memory address space mappings. CPUs went to 64 bit before 4GB was cheap enough for this to be a problem, so no work was done to really reduce the kernel address space footprint (or to separate the address spaces altogether).

Actually, although what you say is true, the OP was also entirely correct in noting that hardware sometimes makes large regions of memory unavailable, even in relatively recent computers. The situation in question is independent of the OS memory model, although that has its own implications for memory use.

PCI memory mapped IO needs to be put somewhere at a physical address that the CPU is able to access. Although since the Pentium Pro it's been possible for x86 machines to address 36 bits of physical address space, some motherboards only actually give them 32 address lines to use.

If you stick 4GB of RAM in such a box then the memory mapped IO regions need to go somewhere that the CPU can still address them using only 32 address lines. Since the CPU has only 2^32 bytes = 4GB addressable this necessarily means that they have to alias real RAM regions. Those RAM regions are rendered inaccessible. There's nothing you can do to get them back, either - you can't remap them to a different place because you're limited by the 32 physical address lines. This is sometimes called a "memory hole".

This is compounded by the fact that some BIOSes are worse at allocating memory mapped IO spaces than others. They sometimes seem to use up hundreds of megabytes for these IO regions. I think that's more a case of the allocation policies being stupid than that quantity of addressable memory actually being needed. The problem isn't entirely trivial, though, since I think PCI devices can request certain alignments of their memory regions, so they can't just be placed anywhere.

Event 32-bit server grade hardware typically offers support for the CPU physically to address more than 32-bits of physical memory, enabling these systems to play games with remapping memory to make all 4G (or more) of RAM be accessible, whilst providing the necessary MMIO regions. Those of us who are using lower grade hardware (me, for instance!) are limited to smaller memory sizes by the motherboard, regardless of what the CPU chip and OS are capable of addressing.

I was not pleased when I discovered my own machines suffered from this "feature" but equally well I was pleased when I got this machine cheap. I guess you can't have everything!

Re:What's more

[Doctor Faustus]

Actually, I recall x86's real mode pages actually overlapped in the bus address ranges that they mapped to. So in this case number of pages * page size doesn't give total addressable real memory. Can't remember the actual numbers, however.
You seem to be the first one to remember the gist of it. The 8086 had 16 bit pointers (I think there was another term) and 16 bit segments. The physical address was Segment*16 + pointer, meaning only the four least significant bits were identified entirely by the simple pointer and there was effectively 20 bit addressing, for 1MB of addressable memory.

According to my x86 assembler teacher (this is the guy who taught us to time delays by calculating cycles and clock speed, so take it with a grain of salt), the idea was to allow programs to use hard-coded pointer values, while the segment would let the program be put wherever in memory it actually fit. I was taking x86 assembler from the EE department at the time, and when I asked my SPARC assembler teacher in the CS department how SPARC did it, he said that everything there used relative pointers.

I turn 32 in three weeks. I should not be filling in details that were before everyone else's time.

Re:What's more

[Lemming Mark]

You seem to be the first one to remember the gist of it. The 8086 had 16 bit pointers (I think there was another term) and 16 bit segments. The physical address was Segment*16 + pointer, meaning only the four least significant bits were identified entirely by the simple pointer and there was effectively 20 bit addressing, for 1MB of addressable memory.

Ah, thanks for that. Yes, that's what I was remembering but you remembered it better :-)

FWIW, I suspect the "pointers" were probably called something like "logical addresses" or "linear addresses", I can't remember which... x86 has some funny addressing terminology of its own and I think those terms come up when talking about protected mode; I suspect they come up with a slightly different meaning in 8086 as well.

According to my x86 assembler teacher (this is the guy who taught us to time delays by calculating cycles and clock speed, so take it with a grain of salt), the idea was to allow programs to use hard-coded pointer values, while the segment would let the program be put wherever in memory it actually fit. I was taking x86 assembler from the EE department at the time, and when I asked my SPARC assembler teacher in the CS department how SPARC did it, he said that everything there used relative pointers.

For some reason I genuinely expected you to say "when I asked my SPARC teacher how that CPU did it, he laughed" - I suspect SPARC would have done something somewhat more sane from the start ;-) That's only a guess though, maybe I'm being optimistic! SPARC has it's own crazy functionality, as do all chips but it's still hard to beat x86 for general across-the-board insanity (in my opinion!).

I turn 32 in three weeks. I should not be filling in details that were before everyone else's time.

It's quite nice to give this knowledge a dust off once in a while - it was really interesting to have this discussion even though I don't really need to know it.

A nice bit of trivia is that modern x86 processors support something called "big real mode". In real mode on an x86, you can only load segment descriptors that make sense in real mode. So it won't let you, for instance, load a segment descriptor that addresses memory above real mode's normal limit (1MB, I suppose from your description). However, you can switch to protected mode and load that segment descriptor, no problem, as it's valid there. The scary thing is that you can switch back to real mode and leave the segment descriptor in place - and it works, at least for some cases. Big real mode involves pulling that stunt so that you end up with real mode execution but able to access all the machine's memory. And apparently that's a feature, not a bug - some OSes / bootloaders actually expect this.

Anyhow, this stuff may be before everyone else's time. I'm turning 26 at around the time you turn 32 but I've had to grub through it a fair bit in the past few years. In another 10 years I expect either you and I will be sitting back and trying to explain to the young kids of today how computers used to be ....... or, we'll still all be using some future x86 chips that will still support all this in hardware. I shudder to think!

Re:Thank God

[tthomas48]

They were slightly older tech in 1983. But that only makes it more likely a teenager would have one.

Re:My favorite 'scare'

[bunratty]

That's from the Weekly World News. It was a parody of tabloids. The sad thing is that tabloids are already so outrageous that many didn't realize that the WWN was a spoof.

Re:Obligatory "WarGames" quote...

[TenBrothers]

You have no idea what the quote means. "I'd piss on a sparkplug if I thought it'd do any good" means that you're open to trying ANY solution to fix the problem. Not simply the foolhardiest solution.

Re:It Was Close

[asackett]

I call bullshit. Y'see, I was in the USAF Space Command at the time, in Missile Warning and Space Surveillance. There were no dialup modems to which you and your buddies could connect, no external connections to MILNET at all.

Re:Lies!

[Miseph]

Frighteningly close? Really?

Perhaps if the real inventors of the internet hadn't basically come out and validated his quote in full, you could get away with saying that, but since they did (and since you took that snippet out of a context that actually explains HOW he did it) I'm left with you having some axe to grind with Gore (and I can't imagine what it is at this point).

Anyway, for anyone out there who still thinks that gore even misspoke... he claimed to have taken initiative in creating the legislation which created (largely by funding) a larger version of ARPAnet that was accessible to the public at large. In other words, he has never claimed any (direct) technical contribution to the internet, but has claimed legislative, financial, legal, and social contributions to it. This makes sense, if you keep in mind that there are ways to contribute to technology other than coding.

Sorry, but he *DID* INDEED say it

[DrYak]

No. He actually never said that. Not once. He did say it. Only not with these words with which it is usually reported.
From Wikiquote (Where you can find to pointers to the source) :

I laid out memory so the bottom 640K was general purpose RAM and the upper 384 I reserved for video and ROM, and things like that. That is why they talk about the 640K limit. {...} It was ten times what we had before. But to my surprise, we ran out of that address base for applications withinâ"oh five or six years people were complaining. Also:

I have to say that in 1981, making those decisions, I felt like I was providing enough freedom for 10 years. That is, a move from 64k to 640k felt like something that would last a great deal of time. Well, it didn't - it took about only 6 years before people started to see that as a real problem. So basically he didn't say that "640k will probably be enough for everyone". He said that he "organised the memory layout such as only the first 640k are available to map memory and he was persuaded that was it was enough for ten years because it was 10x more than before".

That means he had some influence on IBM to help them choose a layout. Of all different combination of layout, he went for the one that is hard to extend and is going to be a big problem down the line (rather than putting the ROM first, so ALL the address space after the BIOS is free for memory access, or a mechanism which would allow the BIOS to be mapped to any address space - which would have extended the address space of 16bits softwares up to 1MiB + 64KiB),

Re:Sorry, but he *DID* INDEED say it

[Samah]

Sorry, but no.

Straight from the horse's mouth:
http://www.usnews.com/usnews/biztech/gatesivu.htm
http://www.wired.com/politics/law/news/1997/01/1484

And part of the reason it's misattributed:
http://www.nybooks.com/articles/15180#fn*

He *implied* that 640k was a fair amount "for the time being" but that it would need to be significantly increased as technology proved more demanding. He never implied that "no-one will ever need more than 640k".

Re:It Was Close

[man_of_mr_e]

If you'd seen the movie, you'd know that they explained that. The breach occured through an external contractor who was on a secure network that allowed them backdoor access.

Re:It Was Close

[Undead NDR]

So I ask the Slashdot audience - What other computer/hacker/technology movies out there actually measure up on a technical level?

"Pirates of Silicon Valley" is a very faithful account on Apple and Microsoft's early history. They really got all the details right in that one.

Of course, the fact that the plot isn't fictional certainly helped.

Re:Gee thanks

[Lemming Mark]

Now I'm going to have those nightmares again.

Just quit sleeping, it'll be fine ;-)

I don't think it will probably help if I now remind you that all x86 CPUs, even your spiffy new multicore multi-GHz 64-bit gaming rig boot up believing they are an 8086. Your PC relives that memory management hell every time you switch it on until the software comes along and sets the "you're not a stupid old CPU" flag.

For this reason, it's important to remember not to touch the PC case whilst it's booting, otherwise you might get some real mode ectoplasm on you and be contaminated with insane memory models.

PS, don't have nightmares.

Re:It Was Close

[falconwolf]

There were no dialup modems to which you and your buddies could connect, no external connections to MILNET at all.

Actually there was a way in. Then at UC Berkley Cliff Stole found someone had gained access to a system at Berkley which was then used to access military computers. He later wrote a book, "The Cuckoo's Egg: Tracking a Spy Through the Maze of Computer Espionage", about it. Some crackers, as they didn't follow the hacker ethic I won't call them hackers, in Germany being paid by the KGB was able to gain access. Stole found them because of a 75 cent discrepancy between two computers, the one broken into and an accounting system that tracked usage and billing.

Falcon

phreaking

[falconwolf]

Phreaking (dunno if the portrayal was accurate, but phone booths around these parts fell victim to something not too far removed from what was shown in the movie).

How it was done was even easier than the movie portrayed it, for long distance calls a signal of 2600 Hz would allow free calls. At the tyme Cap'n Crunch included a whistle in the box that produced that signal. So all you needed to do was blow the whistle to make a free call. Blue boxes which made the sound were also made.

Falcon

You want Citations? You can't HANDLE the citations

[mikelieman]

http://www.politechbot.com/p-01394.html

Date: Thu, 28 Sep 2000 17:43:58 -0400
From: vinton g. cerf
To: Declan McCullaugh , farber@cis.upenn.edu
Cc: rkahn@cnri.reston.va.us
Subject: Al Gore and the Internet

Dave and Declan,

I am taking the liberty of sending to you both a brief
summary of Al Gore's Internet involvement, prepared by
Bob Kahn and me. As you know, there have been a seemingly
unending series of jokes chiding the vice president for
his assertion that he "took the initiative in creating
the Internet."

Bob and I believe that the vice president deserves significant
credit for his early recognition of the importance of what has
become the Internet.

I thought you might find this short summary of sufficient
interest to share it with Politech and the IP lists, respectively.

===

Al Gore and the Internet

By Robert Kahn and Vinton Cerf
Al Gore was the first political leader to recognize the importance of the Internet and to promote and support its development.

No one person or even small group of persons exclusively "invented" the Internet. It is the result of many years of ongoing collaboration among people in government and the university community. But as the two people who designed the basic architecture and the core protocols that make the Internet work, we would like to acknowledge VP Gore's contributions as a Congressman, Senator and as Vice President. No other elected official, to our knowledge, has made a greater contribution over a longer period of time.

Last year the Vice President made a straightforward statement on his role. He said: "During my service in the United States Congress I took the initiative in creating the Internet." We don't think, as some people have argued, that Gore intended to claim he "invented" the Internet. Moreover, there is no question in our minds that while serving as Senator, Gore's initiatives had a significant and beneficial effect on the still-evolving Internet. The fact of the matter is that Gore was talking about and promoting the Internet long before most people were listening. We feel it is timely to offer our perspective.

As far back as the 1970s Congressman Gore promoted the idea of high speed telecommunications as an engine for both economic growth and the improvement of our educational system. He was the first elected official to grasp the potential of computer communications to have a broader impact than just improving the conduct of science and scholarship. Though easily forgotten, now, at the time this was an unproven and controversial concept. Our work on the Internet started in 1973 and was based on even earlier work that took place in the mid-late 1960s. But the Internet, as we know it today, was not deployed until 1983. When the Internet was still in the early stages of its deployment, Congressman Gore provided intellectual leadership by helping create the vision of the potential benefits of high speed computing and communication. As an example, he sponsored hearings on how advanced technologies might be put to use in areas like coordinating the response of government agencies to natural disasters and other crises.

As a Senator in the 1980s Gore urged government agencies to consolidate what at the time were several dozen different and unconnected networks into an "Interagency Network." Working in a bi-partisan manner with officials in Ronald Reagan and George Bush's administrations, Gore secured the passage of the High Performance Computing and Communications Act in 1991. This "Gore Act" supported the National Research and Education Network (NREN) initiative that became one of the major vehicles for the spread of the Internet beyond the field of computer science.

As Vice President Gore promoted building the Internet both up and out, as well as releasing the Internet from the control of the government agencies that spawned it. He served as the major administr