Re:SFMTA's Train System Running on Floppy Disks
by sevenseventen on Monday April 08, 2024 @10:07AM
(#39969857)
Can someone just ask Foone or lcamtuf to help them get it running off an internet-connected toothbrush or something? It seems like there are so many people doing complex reverse-engineering of ancient stuff _just for kicks_ that this floppy-disk issue just shouldn't require a massive project.
yes, I know safety-critical systems are different. I also expect that the floppy-disk issue is just the easiest problem to explain of a long chain of terrible legacy lock-ins. However, if they're literally holding their breath every morning when it's time to IPL the system off a floppy...that part sounds solvable.
Re:SFMTA's Train System Running on Floppy Disks
by gojomo on Wednesday April 10, 2024 @02:22PM
(#39994044)
The hypercompetence of tech enthusiasts and the mind-numbing idiocy & dishonesty of politial governance don't mix, so cities have to spend tens of millions with parasitic contractors for what a few clever hackers could do as a side-project.
Re:SFMTA's Train System Running on Floppy Disks
by WaitWaitWha on Monday April 08, 2024 @10:14AM
(#39969926)
>Turns out that in 1998, SFMTA had the latest cutting edge technology when they installed their automatic train control system.
> "We were the first agency in the U.S. to adopt this particular technology but it was from an era that computers didn't have a hard drive so you have to load the software from floppy disks on to the computer,"
In 1998, most personal computers already had hard drives [0]. From Wikipedia "The IBM PC/XT in 1983 included an internal 10 MB HDD, and soon thereafter, internal HDDs proliferated on personal computers."
The 3.5" floppy is from the mid 80's, again from Wiki [1] "In the early 1980s, many manufacturers introduced smaller floppy drives and media in various formats. A consortium of 21 companies eventually settled on a 3½-inch design..."
Re:SFMTA's Train System Running on Floppy Disks
by abeppu on Monday April 08, 2024 @10:32AM
(#39970147)
Given that the agency seems not to be able to cope with change at a reasonable pace, I wonder if 1998 was just when the control system project finished, having been planned and started several years prior.
Re:SFMTA's Train System Running on Floppy Disks
by deathanatos on Wednesday April 10, 2024 @02:53PM
(#39994394)
I'm not sure moving it back a whole decade saves them?
My family's first PC in 1987 had a hard disk. The Wikipedia quote they provide lines up with that, and provides a more authoritative point of when it was introduced.
And yeah, the "5 inch floppy" quote paired with a photo of a diskette. God only knows what actual hardware the system uses. But point being … the journalist doesn't seem to have found out.
Re:SFMTA's Train System Running on Floppy Disks
by gsk22 on Wednesday April 10, 2024 @04:26PM
(#39995352)
There's a big difference when choosing technologies for a home computer versus a safety-critical system that will run for decades. Seems reasonable they would've chosen a proven, if slightly outdated, tech over a newer one that had less data to back up its long-term reliability.
And of course we can get into the discussion of cost: floppies are way cheaper than hard drives, especially for the presumably-small amounts of data that are needed for such a control system. A 500MB hard drive was probably overkill.
I am of course speculating, but I don't know why we should assume that the engineers working on the project originally made a silly decision. They almost certainly weighed the available options to deliver the project within the defined constraints of the system.
Re:SFMTA's Train System Running on Floppy Disks
by JoyousAbandon on Wednesday April 10, 2024 @05:25PM
(#39995893)
Hard drives weren't new in 1998. I don't even know where you'd have gotten a computer that lacked one by then; and most would also have had a CD-ROM drive.
Re:SFMTA's Train System Running on Floppy Disks
by compuguy on Thursday April 11, 2024 @07:32PM
(#40007929)
Yeah, on further reflection, I recall my parents having a 286 with a hard drive. Still don't get why they couldn't find a 5.25" floppy. Then again both types of floppy drives are still quite obsolete....
Re:SFMTA's Train System Running on Floppy Disks
by inferiorhuman on Wednesday April 10, 2024 @02:47PM
(#39994312)
Why do I have to do this research instead of the "journalist"?
Ratchet the snark back. The journalist was referring to the train control system not home computers in someone's basement. And, yes, twenty five years ago SelTrac was cutting edge. Moving block systems were basically unheard of back then.
Re:SFMTA's Train System Running on Floppy Disks
by JoyousAbandon on Wednesday April 10, 2024 @05:23PM
(#39995876)
The only snark here is yours. What are you talking about with "computers in someone's basement?"
He pointed out glaring factual errors in the story, which should not have made it through any kind of editorial review. For example: 25 years ago pretty much every computer had a hard drive. And the disk depicted in the article is obviously a 3.5", not a "five-inch floppy."
Re:SFMTA's Train System Running on Floppy Disks
by jcgrillo on Wednesday April 10, 2024 @07:28PM
(#39996758)
> glaring factual errors
You keep parroting this maxim without showing any convincing evidence of an error... what's the point of that? You obviously have some affinity for factual correctness, yet your style of argument and evidentiary rigor appears to boil down to "repeating the maxim many times in many different places makes it more factually true" which is obviously nonsense. Maybe some food for thought?
Re:SFMTA's Train System Running on Floppy Disks
by inferiorhuman on Wednesday April 10, 2024 @06:11PM
(#39996238)
Whether the computer in your basement had a hard drive or not has no bearing on whether or not SelTrac was cutting edge at the time (it was). That there were even computers with microprocessors put SelTrac decades ahead of what was in use elsewhere at the time.
Re:SFMTA's Train System Running on Floppy Disks
by mschuster91 on Thursday April 11, 2024 @04:24AM
(#39999722)
> And, yes, twenty five years ago SelTrac was cutting edge. Moving block systems were basically unheard of back then.
Meanwhile in Germany, we have had moving blocks from the late 80s, based on a technology developed from the mid-60's and production-ready by the 70s [1]. Incredibly, the LZB technology never had an actual accident happen in all the time, only three "bare misses" (one of which was pretty spectacular in that it caused a train to pass over a switch rated for 80 km/h with around 185 km/h without derailing).
Re:SFMTA's Train System Running on Floppy Disks
by rexpress on Thursday April 11, 2024 @06:09AM
(#40000469)
SelTrac has been around since the mid 80s, and was originally a German developed product (Standard Elektrik Lorenz) based on LZB technology.
My understanding of LZB is limited, but it appears to be a fixed block system with wayside detection of trains, albeit with shorter blocks than lineside signals would usually have. This is different to SelTrac which is moving block.
Re:SFMTA's Train System Running on Floppy Disks
by mschuster91 on Thursday April 11, 2024 @07:04AM
(#40000855)
Yeah, LZB internally is based on fixed blocks - but on a system with block lengths down to 50 meters (as in the Stammstrecke München [1]), the difference is negligible.
Crazy to see that SelTrac was actually developed in Berlin, failed there, but is still in widespread use across the world.
Re:SFMTA's Train System Running on Floppy Disks
by jcgrillo on Wednesday April 10, 2024 @02:51PM
(#39994366)
Why would a hard drive be better? If the floppy fails just grab another off the shelf and try it (surely they have more than one copy). Downtime measured in seconds.
The other good thing about the floppy is it can't hold very much code. So the system has a tight upper bound on how bloated and complex it can get. Simpler systems are more maintainable.
These things seem like great assets for maintaining critical infrastructure.
EDIT: Another great thing is such a system will be stateless. No disks, no filesystems, no databases. Sign me up.
Re:SFMTA's Train System Running on Floppy Disks
by jcgrillo on Wednesday April 10, 2024 @05:44PM
(#39996036)
Where is the factual error? This passage is the one we're taking about right?
> Turns out that in 1998, SFMTA had the latest cutting edge technology when they installed their automatic train control system.
> "We were the first agency in the U.S. to adopt this particular technology but it was from an era that computers didn't have a hard drive so you have to load the software from floppy disks on to the computer,"
The fact of when hard drives became commonplace in personal computers (EDIT: or when 3.5" floppies were introduced) has no bearing whatsoever on whether this transit control system was cutting edge in 1998. This statement is not, at least not obviously, factually incorrect. So if you're going to claim that, show your work.
Re:SFMTA's Train System Running on Floppy Disks
by jampekka on Wednesday April 10, 2024 @08:00PM
(#39996975)
I had the displeasure to operate a sort of industrial/automotive rack computer running very simple Simulink data logging that booted only from a floppy, and I think it was bought around 2008. For a greenfield project.
Probably cost like hell and was decade or two behind in technology, but I didn't buy it and definitely wouldn't have. Salespeople get people to do stupid stuff.
I'd guess these are used a lot in industrial settings where the code and task is actually very simple. Would run no problem with a $1 microcontroller and a hundred lines of C and with a lot less hassle. Likely vendors have gotten a reputation and keep on selling them with FUD.
Re:SFMTA's Train System Running on Floppy Disks
by abeppu on Monday April 08, 2024 @10:01AM
(#39969801)
Frustratingly, though the article goes into how replacing/upgrading the whole control system will be an big, expensive project, they don't attempt to say why they can't just update the "read from floppy" part of the system to read the same info from a modern component.
Re:SFMTA's Train System Running on Floppy Disks
by inferiorhuman on Wednesday April 10, 2024 @03:06PM
(#39994542)
Floppies aren't the problem, the main problem is lack of support. The MTA moved off of OS/2 back in 2008. Yeah, halfway into its intended lifespan Alcatel/Thales basically stopped supporting the whole mess. If I had to guess they're using an equally unsupported version of Windows now.
yes, I know safety-critical systems are different. I also expect that the floppy-disk issue is just the easiest problem to explain of a long chain of terrible legacy lock-ins. However, if they're literally holding their breath every morning when it's time to IPL the system off a floppy...that part sounds solvable.
> "We were the first agency in the U.S. to adopt this particular technology but it was from an era that computers didn't have a hard drive so you have to load the software from floppy disks on to the computer,"
In 1998, most personal computers already had hard drives [0]. From Wikipedia "The IBM PC/XT in 1983 included an internal 10 MB HDD, and soon thereafter, internal HDDs proliferated on personal computers."
The 3.5" floppy is from the mid 80's, again from Wiki [1] "In the early 1980s, many manufacturers introduced smaller floppy drives and media in various formats. A consortium of 21 companies eventually settled on a 3½-inch design..."
[0] https://en.wikipedia.org/wiki/Hard_disk_drive
[1] https://en.wikipedia.org/wiki/Floppy_disk
Why do I have to do this research instead of the "journalist"?
Probably this. Probably they got the plans worked up in 1990, but didn't finish everything until 1998.
Edit: Even the news article hints at 5 inch floppy disks...which makes 1998 make absolutely no sense to me at least.
https://abc7news.com/san-francisco-train-system-has-been-run....
My family's first PC in 1987 had a hard disk. The Wikipedia quote they provide lines up with that, and provides a more authoritative point of when it was introduced.
And yeah, the "5 inch floppy" quote paired with a photo of a diskette. God only knows what actual hardware the system uses. But point being … the journalist doesn't seem to have found out.
And of course we can get into the discussion of cost: floppies are way cheaper than hard drives, especially for the presumably-small amounts of data that are needed for such a control system. A 500MB hard drive was probably overkill.
I am of course speculating, but I don't know why we should assume that the engineers working on the project originally made a silly decision. They almost certainly weighed the available options to deliver the project within the defined constraints of the system.
He pointed out glaring factual errors in the story, which should not have made it through any kind of editorial review. For example: 25 years ago pretty much every computer had a hard drive. And the disk depicted in the article is obviously a 3.5", not a "five-inch floppy."
You keep parroting this maxim without showing any convincing evidence of an error... what's the point of that? You obviously have some affinity for factual correctness, yet your style of argument and evidentiary rigor appears to boil down to "repeating the maxim many times in many different places makes it more factually true" which is obviously nonsense. Maybe some food for thought?
Meanwhile in Germany, we have had moving blocks from the late 80s, based on a technology developed from the mid-60's and production-ready by the 70s [1]. Incredibly, the LZB technology never had an actual accident happen in all the time, only three "bare misses" (one of which was pretty spectacular in that it caused a train to pass over a switch rated for 80 km/h with around 185 km/h without derailing).
[1] https://de.wikipedia.org/wiki/Linienf%C3%B6rmige_Zugbeeinflu...
My understanding of LZB is limited, but it appears to be a fixed block system with wayside detection of trains, albeit with shorter blocks than lineside signals would usually have. This is different to SelTrac which is moving block.
Crazy to see that SelTrac was actually developed in Berlin, failed there, but is still in widespread use across the world.
[1] https://de.wikipedia.org/wiki/Stammstrecke_(S-Bahn_M%C3%BCnc...
The other good thing about the floppy is it can't hold very much code. So the system has a tight upper bound on how bloated and complex it can get. Simpler systems are more maintainable.
These things seem like great assets for maintaining critical infrastructure.
EDIT: Another great thing is such a system will be stateless. No disks, no filesystems, no databases. Sign me up.
(These days, you could also replace the floppy with a USB drive: they make adapters/emulators.)
> Turns out that in 1998, SFMTA had the latest cutting edge technology when they installed their automatic train control system.
> "We were the first agency in the U.S. to adopt this particular technology but it was from an era that computers didn't have a hard drive so you have to load the software from floppy disks on to the computer,"
The fact of when hard drives became commonplace in personal computers (EDIT: or when 3.5" floppies were introduced) has no bearing whatsoever on whether this transit control system was cutting edge in 1998. This statement is not, at least not obviously, factually incorrect. So if you're going to claim that, show your work.
Probably cost like hell and was decade or two behind in technology, but I didn't buy it and definitely wouldn't have. Salespeople get people to do stupid stuff.
I'd guess these are used a lot in industrial settings where the code and task is actually very simple. Would run no problem with a $1 microcontroller and a hundred lines of C and with a lot less hassle. Likely vendors have gotten a reputation and keep on selling them with FUD.