I am using scriptor on Linux to send APDU commands to a SCOSTA card on an ACR39 card reader. I am new to smart card programming. I am trying to do something simple, writing “Hello World” on the card and retrieving it back.

I understand I have to select the MF first, I am doing so using the APDU 00 A4 00 00 02 3F 00. On my console, doing so return 90 00 : Normal processing.

To write the CREATE FILE command, I am considering the documentation here (Section 6.3). It shows the general template of the command as shown below. From the template below, I write the APDU 00 E0 00 00 <length_data_field> <data_field>.

I have the construct the <data_field>. The template given to construct is given below from the documentation here (Section 6.3.2.2.2). This is where I am stuck because I have some confusion in interpreting the table below. How to use this table to create a data field for writing “Hello World” on an EF?

My question is How to use this table to create a data field for writing “Hello World” on an EF?