Computing Myth #1: Software cannot damage hardware February 2, 2006
Posted by Trixter in Technology.trackback
Oh yes it can. Here’s a story for you: In my teens, I had a friend who got the IBM 5155 (the Portable Computer — you know, the heavy luggable one with the monochrome CRT monitor inside it) from a Computerland. He was screwing around with POKE in BASIC and POKE’d a value somewhere into CGA-land, saw some pretty squiggles for about 3 seconds, then poof and we smell the familiar smell of ozone. We went back to Computerland, but they told him that there was no way that software could have damaged hardware and they weren’t going to repair it (thinking that he had dropped it or something). So my friend, with salesman watching with one eye from across the room, walks over to another one on display, takes the diskette out, boots into BASIC, writes a 1-line program, and poof, ozone, and no more monitor. Salesman didn’t quite know what had happened, so my friend walked over to another one on display and does it again, but steps aside so that the salesman can see it this time.
Let me tell you, I’ve never seen an overweight, balding, 50+yr old move so fast. He sprang like a gazelle toward us and for a second I thought I was going to get the crap beaten out of me. Thankfully, all he did was yell, about how we were going to have to pay for that, etc. This got the attention of the manager, who came out and said they’d honor the warranty and fix his machine if the kid would stop blowing up all the IBM 5155 monitors in the store.
Yeah, and a fully-punched card could jam up card readers. Do you have any examples less than 20 years old? :)
My old ATI 8500 had a bug in it with certain invalid resolutions (caused by games crashing etc) that would literally fry my expensive Panasonic 19″ CRT. Thankfully it came with a 3 year warranty, and they would cover it. But it was annoying lugging that thing to the service repairing multiple times. Especially how it was really ATI’s fault.
jim: No modern examples because most people today simply buy into the myths ;-)
But seriously, I don’t think there are many computing myths in 2006 because computers have become part of international culture. They’re household appliances, like televisions or dishwashers or phones. Everything (consumer) is known. So there isn’t really any magic in computers (in general) any more.
On motherboards with fans whose speed can be controlled by software (via ISA bus + I2C), software could e.g. permanently stop the fan on the CPU’s heatsink and cause the CPU to overheat. This would almost definitely have to be done deliberately, though: it seems unlikely to me that someone writing random values to random ports would write the right sequence of bytes to the Super I/O controller’s index and data ports in order to stop the fan.
You could also e.g. program a CD or DVD drive with the wrong firmware and render the drive unusable. You could not do this just by poking values in memory or I/O ports though.
The initial revision of the Motorola 68000 (first chips off the line) had an HCF instruction. “Halt, then Catch Fire.” It caused an infinite loop, which caused the processor to melt.
HCF: not a myth, it was a test instruction left into the original run. It toggles the bus lines so fast that in some configs it burns them out.
Motherboard fans: In order for that to work, you’d also have to disable the alarm/automatic shutdown :-) otherwise the machine would promptly shut off to save itself.
I have a particularly cheap Taiwanese motherboard and although their configuration utility only allows me to throttle back the fans to 40%, speedfan will let me drop them to zero - yes, I checked, they were actually not spinning. Pretty awesome. Even with the bios temp detection, I’d be risking damage if I combined speedfan with superpi.
Omg! This is so true! This is something that happened only a few days ago to me. I was poking around in the VGA memory area with a pointer 0xA0000000L (this is the video memory address for screen mode 0×13). I was unable to directly access the video, so I was randomly writing to the memory. And you know what happened? The picture on the screen started vibrating and poof! I heard a small bang and a flash and some smoke. This happened on my 17″ CRT LG monitor. Can you believe it, this is the latest hardware running on Windows XP, none of the two had any safety measures to stop my program written in Turbo C (16-bit) to meddle around where it isn’t supposed to. So, in fact, it is a myth that “Software cannot damage Hardware”. And trust me, I think it is pretty easy to write a virus that could blow up ur monitor; think about it.
We downloaded a game to two computers and within a week both motherboards had fried. I didn’t believe it but my husband said at the time that it was the game!! Any comments?
Dear Zed, please provide the system configuration, OS, the compiler used and the code that you were writing and we will replicate and test it to see what happens. Ms.Clarke, I am not sure whether a game could possibly damage a systemboard and that too 2 systemboards is kind of very ambiguous. However, we would like to investigate and see what you claim is really possible. Please specify the system configuration and the games that were installed. Also mention the kind of cooling mechanism used if any and also mention if any of the system features were overclocked…. We are very sure that every system failure has a logical reason and can be isolated.
I think I blew the functionality of my built in microphone in my laptop by installing some drivers for the MAC OS X , you know installing that hacked version, uhm I dont know how the rest of the sound works but that thing not, and when I plug an external mic works, so I have no idea, HELPPPPP, its weird..
So, software cannot damage hardware…Ok, then try flashing your bios and disconnect your computer in the middle of the process and see what happens, or better yet, try flashing the BIOS with an incorrect BIOS version
I think you missed the point of the post. Obviously software can damage hardware… that’s why the title has “myth” in it.
Reply to 5: The HCF command halts the processor and reads through all memory locations as fast as possible. It is right that it caused way too much heat for the system to work properly. The only way to stop the HCF is by toggle the RESET line or if something imporiant in the system gets fried.
(Thanks to Google for finding quotes form the BYTE Magazine, Vol 2, December 1977)
Anyway, Do anybody else know about any other undocumented OpCodes?