A Unix-based Logic Analyzer
A circuit I was designing was behaving in unexpected ways:
the output of a wireless serial receiver based on Infineon's TDA5200
was refusing to drive an LS TTL load.
To debug the problem I needed an oscilloscope or a logic analyzer,
but I had none.
I searched the web and located
software to convert the PC's parallel port to a logic analyzer.
I downloaded the 900K program, but that was not the end.
Unfortunately the design of Windows 2000 does not allow direct access
to the I/O ports, so I also downloaded
a parallel port device driver and a program to give the appropriate privileges to other
Finally, I also downloaded from a third site the Borland runtime libraries
required by the logic analyzer.
Needless to say that the combination refused to work.
Continue reading "A Unix-based Logic Analyzer"
Software Complexity: Open Source vs Microsoft
In a readable and interesting paper titled
CyberInsecurity: the cost of a monopoly
seven notable security experts argue that the Microsoft's near monopoly
in the desktop operating system and office productivity markets is creating
a dangerous monoculture that exacerbates the effect of security vulnerabilities.
Continue reading "Software Complexity: Open Source vs Microsoft"
Well-behaved Web Applications
Very few web-based applications are designed to match the
As a result they are often irritating, counteproductive,
or simply unusable.
During the last two months I've been working on an
IEEE Software theme issue titled "developing with
open source software".
Most of my work is performed over the
IEEE Computer Society
The application is an almost perfect example of everything that
is often wrong with such interfaces.
Continue reading "Well-behaved Web Applications"
An Interesting Remote Control
The garage remote control at the place where I work is really
Continue reading "An Interesting Remote Control"
Security researcher beguiled by email spoof
One would expect someone who is reading and contributing to comp.risks
since 1990 to know better, especially if he is also lecturing courses on
IT security, and has written a couple of papers in the area. Maybe it
was also a well deserved punishment for laughing at emails titled
"Valuable business proposition" and "Renew your e-bay account" (who is
so dumb so as to fall for these schemes?)
Continue reading "Security researcher beguiled by email spoof"
I became a FreeBSD committer.
I've been using BSD Unix systems
since 1986 starting with 4.3 BSD on a pair of VAX 780 machines. In
1992, as a bored PhD student, I reimplemented sed(1) and contributed it
the unencumbered BSD version that was then being put together; it is now
part of the *BSD family. I crossed again paths with BSD software when
the prize of the 2000 Usenix technical conference ``win a pet Shark
contest'', Digital's Network Appliance Reference Design-DNARD, came with
a NetBSD boot image. I used that code for drawing about 500 examples
for my book
Code Reading: The Open Source Perspective (Addison-Wesley
2003), detailing how to read software code others have written
Since 2001 I 've been using
FreeBSD to control my home's security, communications, and entertainment
systems as described in a
SANE conference paper
in Personal and Ubiquitous Computing
(as an academic I have to live by the "publish or perish" motto).
Continue reading "FreeBSD Committer"
Code Reading: The Open Source Perspective
In July 2000, while working on a paper on the use of slicing for
choosing parts of an application to develop in a scripting language
(don't ask), I found myself searching open-source programs for
motivating examples, and experimenting with a tool for annotating the
corresponding source code. At some point, a loud click sound in my mind
brought to my attention the fact that although most books and courses
teach us how to program, we actually spend most of our time reading code
others have written. I reasoned that by applying my annotation tool on
open source software I could write a book to present the ideas,
techniques, and tools that go behind code reading.
Continue reading "Code Reading: The Open Source Perspective"