Hi Mathew,
I have worked on SLE series smartcards.

Here is what you need.

SLE4442 has got PSC (Security)Code. This PSC code is programmable. When the blank cards are shipped from the manufacturer, they have a default PSC code of 0xff, 0xff, oxff.

Now comes the usage part:

The cards are having memory which can be read or written. For reading, you do not need the PSC code. But for writing into the card you DO NEED the PSC code. So before you issue any writing command to the card you have to do the PSC code verification. This validation is valid till power ON. So if you do not switch OFF the power to the smartcard, then for further writing you do not need to do PSC verification. Even if you do it does not have any effect, unless you give a wrong PSC code.

Before you change the default PSC code, you must do PSC verification with the default value (3 0xff). If you do not do it, then writing is disabled.

Note: It is NOT necessary that you should change the PSC code, you can keep the code as it is (3 0xff); but PSC code verification must be done atleast once before writing any data into the card.

Once you change the PSC code, make it a point to note it down where you can know the PSC code. Once the PSC code is changed by you, then you are the only person in the world who can write into that card. So if you forget that code, then that card is pure garbage.

PRECAUTION: If you fail to do PSC verification 3 times, the card will never ever accept PSC code even if they are valid codes after 3 wrong attempts. So the card turns garbage again. Understand this feature very well, before you send the PSC codes.
If you attempt 2 wrong PSC verification, and if the third time is sucessful, then also the PSC code verification counter resets to 0 attempts, so you can do another 3 more wrong PSC code verification attempts.
Under any circumstances, do NOT let this PSC attempts counter to count to 3, if it does, then the garbage can is waiting for this card.

Bye and Happy programming,

Mr. Kiran V. Sutar.