Sharp's ER-A440 is very easy to program.
I believe you are talking about a store POS system or Point of sale machine. This is used to cash out payments made by a customer for goods or services.
Hypercom T7p Terminal 512k Credit Card Pos Machine would work well with older equipment.
Rom test
It's very easy to configure POS machines for frontline, heavy use.
Intuit has a POS program that can be used on a smartphone. It is used by plugging in a reader into the headphone jack.It is relatively fast. It also feeds right into the intuit program on your computer.
Point Of Sale (POS) machine is a terminal or part of the checkout process that processes credit or debit cards and finalizes the transaction.
All POS machines will be roughly the same in this area, so it's largely a matter of preference.
It really depends on your card merchants. Call VISA, MasterCard or AMEX to see which POS machines they suggest.
To process payments using a credit card POS machine, you need to follow these steps: Enter the purchase amount on the POS machine. Swipe or insert the customer's credit card into the machine. Wait for the transaction to be authorized by the card issuer. Ask the customer to sign the receipt or enter their PIN. Print or email the receipt for the customer. Complete the transaction and provide the customer with their goods or services.
Roman shades are easiest because they can be washed in the machine.
Mechanical
Well, you can get a free pos for your toolkit at the Microsoft Tech Center and download a free Windows 7 Embedded POSReady Toolkit as a program on the website.