An '86 Skylark sends a total of 26 - 9 bit bytes. The start byte is marked by 9 Logical 1's. The following 25 bytes have a start bit of logical 0, followed by 8 bits of binary data, in order of most significant bit first. Apparently the number of bytes and byte length can be different for different cars. I haven't yet determined what all of the bytes represent because I can't drive the car with it hooked up to my home computer :) That information will be placed here as soon as I get a version of the program to run on my pathetic laptop. In the meantime, check out Daniel Burk's ALDL Information Page (see the main page for a link) which probably provides all the information you would ever need anyway :) -Sean