RFID based security/attendance system

hello sir...
plz could u explain the circuit of these projects....
for eg,wat is A,B,C,D wat is the RFID reader IC....why is the regulator separately drawn...where to use it.
plzz can u throw sum light on these queries and plz could u explain the circuit.....also the description says 8051 but 8952 is used i noe it dusnt matter but i was worried abut the ic pinout.......
plz reply asap....
thanx

Hi, sorry for late reply. Actually, the author sent me wrong files in the zip archive for "RFID based attendance system". I have updated the zip file on the server and now you can download again.

So you can see the new circuit for RFID based attendance system, there A is used, which is a off-page connector label. that means, its connected to label A mentioned on the second circuit diagram, i.e. the A of pin 10 of 89S52 is connected with pin 6 of RFID reader.

Please do not confuse yourself with 8051 architecture and 89s52 IC. please tell me if you want to know anything more..

and forgot to tell you about the RFID reader. please take a look at this http://www.sparrl.com/pages/rfid.htm