Steps to flash 1999 POS machine:

1. Check whether the power supply is plugged in and whether the phone line is connected to the POS machine.

2. After turning on the computer, the first step is to sign in. To sign in, generally press the 1 button, enter the teller number, enter the password, and wait for the connection.

3. Then press the confirmation button to enter the system. The machine will display Swipe Card. At this time, check the card number and press OK.

4. Enter the amount (at this time, the "0" key carries forward and the "clear" key returns).

5. When correct, press Confirm and you will be prompted to enter the password.

6. The customer enters the password on the small keyboard and presses OK, and the consumption receipt is automatically printed (the card swiping is successful at this time).

7. The customer signs the receipt and checks whether the signature is consistent with the signature on the back of the card, and it is done.