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> Pay for rides on all transit services with cash value on your Clipper card.
> Maximum allowed value is $255.
huh, what a weirdly specific value /s
(although, i'm kinda curious about the binary representation now, considering they can go negative)
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@nyanotech it’s also decimal isn’t it?
@nyanotech could be an 8Q7 with sign bit but that’s already pretty cursed for a system built this century
@nyanotech before the advent of connected vehicles, a lot of these bus/tram e-pass cards just stored the balance on the card with nothing so much as a checksum. I once tweaked my balance down by a penny to verify that it worked.
not super smart to try to defraud the operators, though, because the travel records are uploaded at the station and they can audit them vs. top-up records. doesn't take much to get caught, and I heard stories of big fines and prosecution.
@gsuberland @nyanotech a lot of them still do this, but with ostensibly more secure *cards* (i.e. the thing that prevents you from tampering with your balance is the NFC chip's tamper-resistance (at least in offline mode))
@mimir @nyanotech the trick I've seen with those is cloning the real card to a hacked NFC card with all sectors unlocked, tweaking the values, and printing onto the cards so they look like the real deal.
a few years back a group of guys from Leicester got caught doing this as an online service for hacked London Underground passes. made millions, right up until they got handed long jail sentences.
@mimir @nyanotech it was certainly a lot easier in the earlier days of Oyster cards, before they mandated replacement of all of them with newer fancier NFCs that were harder to crack.
can't remember if it was also Oyster cards or one of the other UK rail passes, but there was another case where a technician who worked on the readers was running a side business selling dodgy cards that didn't charge you (maybe some kind of staff access pass?) - again, caught & jailed
@mimir @gsuberland @nyanotech Im guessing this is just so if the servers go down people don't get stranded without transit?
@mimir @gsuberland @nyanotech especially in cases where the terminals are on a moving vehicle without a stable network connection
@cinebox @mimir @gsuberland yeah, clipper is stored-value (and a lot of the bus readers are still offline afaik)
@nyanotech @mimir @gsuberland huh, that explains why the apple wallet version can only live on one device at a time
@nyanotech I wonder if they can only go “negative" based on another value stored for a ride in progress on the card.
@nyanotech hello yes i'd like to add -1 to my balance