Dear PicList:

I am DIY'ing a multiple input access control reader able to decode Temic
E5530 transponder samples. I need a checksum algorithm to verify valid
reads. I can decode all of the number and find a(seemingly) random No in
the checksum location (relative to other known data). Temic won't admit
to any valid checksum on the part other than on their *.PDF sheet and
their official position is that it is unavailable unless I am using 1 ,
0 0 0 , 0 0 0  parts per year !(no chicken, no egg) They ARE however
quite happy for me to use the "NEW AND IMPROVED BELLS AND WISTLES"
E5550K-PP version.

Does anyone know of a checksum algorithm for the samples? (E6 header)

Else: does anyone know why Temics samples don't fully match the spec
sheet?

I'm seriously considering customising PIC12C508 into transponders+ else
does anyone know of a serialised transponder manufacturer/distributor
able to deal with "start up" quantities ?

ps I am using PIC16C715s on this as my 71s and then 711s got toooo fuul
of I2C, ASYNC serial and other comms (including the much mentioned
Dallas iButton 1 wire(with CRC))

pps does any manufacturer want to conquer the Access Control Reader
market?

Thanx in advance all pic[OT] recievers,

Graham Daniel.