Some ALDL questions

[steve ravet]

> My experience with ALDL has been more from a learning point of
> view... haven't actually gotten any code.  I made the interface as
> depicted on my website, and tested it in an isolated fashion, and it
> seems okay.  Attached it to my PC, but haven't gotten any codes from
> the GM 3.8L engine in the garage, since I don't have a terminal
> software package that goes down to 160 baud.  What I planned on
> doing towards the end of the summer once I have a basic frame under
> construction, was to try and write a simple terminal program in C to
> read the serial port.  If this doesn't work, I have a neat U-ART
> sitting in my basement (finding it is going to be a pleasure!) that
> can adapt to almost any baud depending on the clock I drive it with.
>  Something like 160 baud should be incredibly easy to emulate.
> 

Hello, hello?  Is this thing on?  My mail must not be getting thru.  
I have a fax of information about the 160 baud ALDL stream.  From 
that fax, it is clear that no UART will ever be able to read the 160 
baud stream.  It simply is not at all RS-232 compatible.  I posted a 
complete description some time ago to the list, maybe October?  A 
search of the archives will turn it up.  The baud rate is not the 
problem, it's the waveform.  Every bit is preceded by a clock edge, 
some period of time after the clock edge you sample for the bit.  It 
probably wouldn't be hard to make a little pal that would collect the 
bits into a byte, and present them to a parallel port, or feed them 
to a UART, or something like that.

--steve