A short update on 7816: from the 1997 edition of 7816-3, the synchronous
(memory) card material was removed from this part of the spec, and a new
part dedicated to synchronous cards, 7816-10, was prepared and published in
December 1999. From a March 97 draft (sorry, I haven't got the fianl
version), the size coding is extended to at least 4096 data units:
0101 2048
0110 4096
It looks from the draft as if the terminal must check for the first 8 bits
of the ATR to have the value xxxx0010 (x2H), and then the 2nd 8 bits code
for the data unit size and number of data units - but someone with the
published version of 7816-10 ought to be able to verify this.
You are still left with the risk that the card that someone puts into the
reader might not be coded like this, because some of the ISO information is
marked 'informative'.
Regards,
Peter Tomlinson
[EMAIL PROTECTED]
----- Original Message -----
From: "Guillaume LAISNEY" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Friday, December 08, 2000 9:05 AM
Subject: RE: MUSCLE how to get the size of a memorycard?
> Hello,
>
> You can get the size of a memory card from the second byte of its ATR.
> According to ISO 7816-3, the 3 LSB of this byte define the length of data
> units (in bits), and its 4 next bits, the number of data units as :
>
> 0000 = No size specified
> 0001 = 128 data units
> 0010 = 256
> 0011 = 512
> 0100 = 1024
> 0101 = ???
> ...
>
>
>
> Example :
> ATR = 92 23 10 91
> 23 -> 0 0100 011 -> 0100 data units , 011 bits per data unit
>
> This card is a 1 kb memorycard...
>
>
> Regards.
>
> Guillaume.
>
>
> _________________________________
>
> Guillaume LAISNEY
> REALTRONIC - service R&D logiciel
>
> email: [EMAIL PROTECTED]
>
> tel: +33 (0) 2 33 50 98 00
> fax: +33 (0) 2 33 50 98 49
>
> REALTRONIC
> Z.I. Conillot
> 50400 Granville
> FRANCE
>
>
>
> ***************************************************************
> Linux Smart Card Developers - M.U.S.C.L.E.
> (Movement for the Use of Smart Cards in a Linux Environment)
> http://www.linuxnet.com/smartcard/index.html
> ***************************************************************
>
***************************************************************
Linux Smart Card Developers - M.U.S.C.L.E.
(Movement for the Use of Smart Cards in a Linux Environment)
http://www.linuxnet.com/smartcard/index.html
***************************************************************
