Unix History: Why does hexdump default to word alignment?

[geoffrey mendelson]

On Dec 2, 2011, at 9:28 AM, guy keren wrote:
>
> you can use a debugger only for the basic code. you cannot use a  
> debugger when you're dealing with multiple threads that access the  
> same shared data and could have race conditions. in those cases you  
> need to run a test, find that the eventual data is incorrect, and  
> track back using logs and friends, to find the culprit(s).
>
> this is the common case in storage systems - but also in other types  
> of systems.



You also can't use it for the data stored in those systems. Not Linux  
related, except that I want to use Linux based FOSS tools to work with  
it, is something I do. I have several devices which use embedded  
systems which were developed in the 1980's. Mine and the ones others  
bring have range in age from the early 1990's to newer devices, but  
believe it or not, they are still manufactured and sold today.

They are highly proprietary and the software to program them has never  
been reverse engineered, although some portions of the data files  
downloaded to them for programing have.

The reverse engineered portions are documented, BUT they all refer to  
a program called Hex Workshop, which only runs under windows and costs  
$100. Not something the casual user will buy.

These particular devices use various checksums and the program has to  
be able to calculate them properly, even if you then have to manually  
insert them into files.

There are lots of other devices like that, and although people rarely  
think of them these days, a good hex editor with checksum calculators,  
and other utilities is essential.

One of the ironies of the whole process is that these devices use  
microprocessors that were popular in home/small business computers in  
the 1970's and 1980's, now reduced to low power CMOS versions in high  
density surface mount, lead free packages. :-)

Meanwhile, while I am at it, I have to keep a running MS/DOS system  
for the programing software to run. They run most of the time on  
FREEDOS, but not 100%.

Geoff.

-- 
Geoffrey S. Mendelson,  N3OWJ/4X1GM
My high blood pressure medicine reduces my midichlorian count. :-(