my pci is a 16198262 remanufactured by delco which is from what I have read is the same as a 1227730 the chip code is AZTY for a 90 firebird with a 3.1 engine I have read that it uses a 27c256 eprom and also have read that it uses a 27c512 eprom, I have been able to read and save the bin and able to view with hex editor and able to use tunerpro rt with mask $88 and view changeable prameters but when I read with my programmer ( which is a willem's dual ) as a 27c256 and view in hex editer its almost blank, so I assume that it is a 27c512 because it shows data in hex editor is this correct?

AZTY is a '256 kb BIN (32 KB). Although GM may have used a '512 kb chip.

There are copies of AZTY all over the 'net. So you should be able to get a copy for double checking what you read from the chip.

RBob.

Ok I figured out what I was doing wrong I was positioning the eprom at the top of the zif socket on my reader and it needed to be positioned from the bottom to up position in other words I had pin one two holes high eprom is a 28 pin the zif socket is a 32 pin. it is a 256k chip and comparing what I was able to read with the bin on the net it is almost the same. thanks for the info RBob