Gibson Research has provided a free online method of checking if the computer you are using to connect to the Internet has any security holes open to hackers.

At http://grc.com the Shields Up program. My computer, on which I have installed the free Zone Alarm firewall program (http://www.zonealarm.com) passed with flying colours.

In scanning for open ports, Shields Up failed to detect my computer online, which is a good sign. If the software had detected a computer's ports as "closed" or "open", this would tell scanners there was a computer that was available to be hijacked, either to be used as a jumping off point for attacks or for storage of information.

"There's one additional benefit: scanners are actually hurt by probing this machine!" the readout on one of the two scans performed on my machine.

"You may have noticed how slowly the probing proceeded. This was caused by your firewall. It was required, since your firewall is discarding the connection-attempt messages sent to your ports. A non-firewalled PC responds immediately that a connection is either refused or accepted, telling a scanner that it's found a live one... and allowing it to get on with its scanning.

But your firewall is acting like a black hole for TCP/IP packets! This means that it's necessary for a scanner to sit around and wait for the maximum round-trip time possible - across the entire Net, into your machine, and back again - before it can safely conclude that there's no computer at the other end."

I love the idea of being a black hole to hackers.

The next time you use a fax machine, spare a thought to Dr. Rudolf Hell, who died on 11 March aged 100.

Dr. Hell, a German, was a pioneer in the printing and media industry and it's worth detailing his part in history as an illustration as to how technological developments proceed, in part by a flash of inspiration, and in part by incremental steps.

Dr. Hell was born December 19, 1901 in Bavaria, the same month Guglielmo Marconi succeeded in transmitting radio signals across the Atlantic. He came to prominence during the 1920s for inventing an automatic direction finder for aircraft navigation, the forerunner of the auto-pilot, and for an image scanning tube for televisions.

In 1929 he patented a "device for the electric transmission of written characters", which was named the Hellschreiber, or "Hell Recorder", considered to be the precursor to current fax technology.

The machine transmitted text by electronically breaking letters into a stream of dots reassembled at the receiving end. Dr. Hell owed the development of his system to the work done by Scottish inventor, Alexander Bain, who was granted a patent for a prototype fax machine back in 1843.

Bain's "recording telegraph's" sending device used a stylus attached to a pendulum, which passed over metal type to sense light or dark spots on the metal plated "document" being sent.

A pendulum on the receiving device then made a stain on chemically treated paper when an electric charge, which signifies a "dark" spot, is sent down a telegraph line. Hell improved on the method of transmission of the document.

"Hellschreiber is an asynchronous transfer mode where the signal is discretely coded," says HF-Fax, a German Internet site devoted to the development of image transmission. "This means two things: the transmitter does not tell the receiver how fast it transmits. It simply sends the message in it's own speed and the receiver must do it's best."

Doesn't this sound distantly akin to the language used to describe the Internet's method of sending packets of information down a line, which are then re-assembled at the reception point? The Hellschreiber method of communications technology was less prone to poor reception than telex transmissions, making the Hellschreiber popular with news agencies, the post office, and police departments.

The development got a boost in a failed experiment when in 1939 about 1,000 US households were equipped with fax receivers that could electronically print morning newspapers overnight. Experimental fax radio station W9XZY, operated by the St. Louis Post-Dispatch, broadcast the first of the Post-Dispatch's radio edition in February of that year, consisting of nine pages - 8 1/2 inches long. According to the Dead Media Project site, the machine took 15 minutes to produce one page (www.deadmedia.org).

Check out the photographs from a report at that time of six children attempting to read the daily news from a long strip of paper produced during the night. During the Second World War in Nazi Germany, Dr. Hell worked on encoding machines and acoustic mine exploders. After the war he started a new company, Dr. Ing. Rudolf Hell GmbH, and went on to invent an electronically controlled printing block engraver, the Klischograph, making it easier for newspapers to publish photos. He produced an early version of a colour scanner in 1963 and in 1964 invented the Digiset, the first digital typesetter.

His company was taken over by Siemens in 1981 and in 1990 was merged into Linotype AG to become Linotype-Hell AG. Heidelberger Druckmaschinen AG took over Linotype-Hell AG in 1996.

One can see the spinoffs and the entrepreneurship that allowed his company to expand into related areas, such as printing presses, type, scanning, and other key pillars needed for mechanising and improving the quality of modern media technology. All of this from a focus on transmitting information from one place to another.

Factoids of the week: Each security breach costs UK businesses an average of ?77,000, according to a survey by KPMG.

Experienced programmers make on average one error for every 10 lines of code they write according to the Economist, in an article calling for a lemon law for software.

Tech Tattle deals with topics relating to technology. You can contact Ahmed at editoroffshoreon.com or (33) 467901474.