I would definitely be very interested in a generalized inside view of how everything works! I stumbled on some PCMCIA-slot card readers at one point, which led

I would definitely be very interested in a generalized inside view of how everything works! I stumbled on some PCMCIA-slot card readers at one point, which led me on a fun adventure discovering that I can list recent transactions out of my bank card. (Then after losing my wallet (annoying but not tragic) I discovered (to my initial confusion) that the latest model doesn't include this nice "feature". Hmph.) Learning how bankcards worked was very interesting. And - facepalm - of course the terminals I referred to are running their own firmware: Medicare cards do indeed use magnetic stripes. I'm currently headscratching over how authentication/access cards work, and the associated various industry thrashings (standardization, PGP crypto, cloneability, etc).