Hacker Newsnew | past | comments | ask | show | jobs | submitlogin

"Interestingly enough, track 12 does not only contain information pertaining to the last use, but also to the use before that."

This might explain why the system sometimes asks you to "Swipe again" when going through the turnstiles. maybe the write failed?

In the 90s the system had tokens. Someone figured out a cheap way to game the system using inexpensive South American coins..

https://news.google.com/newspapers?nid=1955&dat=19951206&id=...



Wouldn't the most likely reason to "Swipe again" be that the read failed?


The display sometimes reads "Swipe Again At This Turnstile," which might imply that data corruption would occur if you swiped elsewhere...


I once saw that when using a pay-per-ride metrocard and swiped at a different turnstile. I ended up having two rides deducted instead of just one, so I lost a swipe.




Guidelines | FAQ | Lists | API | Security | Legal | Apply to YC | Contact

Search: