Neil Williams wrote:
"Adam H. Kerman" wrote:

Uh, always? What do you do at a fuel station which requires a credit
card before dispensing fuel, or at a restaurant, when the tip amount
to be charged is not known until later

In the latter case, you usually enter the tip into the machine before
giving your PIN.

Interesting. Thank you.

Is the terminal the waiter brings to your table exchanging telemetry
wirelessly during the transaction, or does it have to be plugged into
a base station elsewhere in the restaurant? I assume it's wireless.

Are they robust enough to be used where fare collection with a hand-
held device is warranted, if gawd forbid we talk about transport, or
would a more robust hand-held device be used on trains?