GM's ALDL info

[Oliver Scholz]

Ven Polychronakos writes:

>Could you post a summary of the replies you got?
>Thanks,  Ven

Considering the interest in the information, it think a summary is
justified.

Here's what I know:

The ALDL uses a TTL level output (1=H=5V, 0=L=0V) with 8192 Baud.
A word consists of 10 Bits, the startbit (L), 8 data bits (LSB first) and
one stop bit (H). The line is idle high.
The ECM sends packets that look like this:

1 byte device code
1 byte: 85+N (N being the length of the data part of the packet)
N data bytes
1 byte checksum

between two packets the line goes idle (H) for at least 10 bit times.

Information still missing includes: A list of device codes, the interpretation
of the data bytes and how to compute the checksum (which I probably could
find out myself... I guess it's just adding up the data part of the package.

So, once again, if anyone has any further information, please let me know
(or better yet, post to the net. I know a *bunch* of people is interested
in this!)

-Oliver