Long...Re: Programming $65

[Mike Pitts]

>Your post happened to be the proverbial straw, nothing personal.

Ditto. 8-)

>Sure.  But how to remember the facts without putting them to use?  Do
>you know the bore and stroke for all the Packard engines made? 

The important thing is to know what bore and stroke mean as 
they apply to an engine.  And then how to use the values when 
you have them.  Good analogy.   Sort of like a class properties 
and an instance.  You could have bore and stroke properties 
of an engine class, where your packard values would simply 
be associated with only the packard engine class instance. 

(You don't need to know OOP for PCM reversal....yet)

>Is it common for an Eprom burner to output data in hex format?

There are three common formats.  Binary (hex), Moto-S and Intel. 
Moto-S seems to be the most popular, but I prefer binary.

>If so, why do Motorola debuggers use Sxx format?

Because it's their company's standard I think.

>What is Sxx format?

Moto's ASCII representation of binary data with headers and 
checksums appended to each line.

>Can hex data be converted to Sxx format?  How?

Yes.  I use my eprom programmer software to read it in as 
binary, then I write it back out selecting Moto-S as the format. 

>Since learning often involves small steps, I'd like to be able to
>learn some of the Motorola assy language, then make it do something,
>each step building on the last.  What can I go for the "do something"
>part?

Look at some of the reversed code that has been presented 
on this list.  See what the instructions are doing.  Keep the Moto 
asm book close by.  Mine is almost worn out.  8-) 

Then try reversing small pieces yourself.

>Is there some type of "simple to complex" ladder of Motorola
>processors that are closely enough related to learn on the "simple"
>and move to "complex"?  Is this the long way around?

Not necessary.  The 6801's of the C3 era and the HC11's in later 
PCM's are so similar, it's okay to start with either.  The HC11 just 
has a few more op codes.  (Which IMO actually makes it a easier)

>I've tried doing some Intel assy stuff out of a book, using a freeware
>assembler, and the book's own programs don't work.  Are there many
>variations in x86 assy language?

If you are going to stick with GM ECM's, I wouldn't worry about Intel 
x86 asm, at least for now.  But yes, there are variations.  Again, the 
later processors usually have additional instructions.


-Mike