Hi Dave I have a problem using SCardTransmit() to transmit a case 4 command to a T=1 card. For some reason, SCardTransmit() does it's own calculation for the length expected in the response APDU from the card. Somewhere in the code it says dwRxLength = pbSendBuffer[4] + 2; /* CLA INS P1 P2 Lr Data SW1 SW2 */ This may work in T=0, were a case 4 command is split into the command itself and a subsequent GET REPONSE, but it fails for T=1. In the later case, the APDU is CLA INS P1 P2 Lc Data Le. I would completely remove the variable dwRxLength and pass pcbRecvLength directly to IFDTransmit. Otherwise things would get even more complicated for APDU's with extensed length fields or for command APDU's that use Le=00. I'm using a SELECT FILE with FID=3F 00 in a command APDU CLA INS P1 P2 Lc Data Le 00 A4 00 00 02 3F 00 00 which will return the File Control Information (FCI) for most MFCs using T=1. In T=0 this would map io CLA INS P1 P2 P3 Data 00 A4 00 00 02 3F 00 GET RESPONSE CLA INS P1 P2 P3 Data 00 C0 00 00 (SW2) <fci> Andreas -- Andreas Schwier Tel. +49 171 8334920 CardContact Software & System Consulting http://www.cardcontact.de *************************************************************** 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 ***************************************************************
