My Inventions: the TILLEGRAAF linedriver and PLECTOR asynchronous multiplexer.

Tillegraaf

In 1975 I developed the “Tillegraaf” baseband modem at the AKZO chemical company research laboratoria in Arnhem NL , to be able for us to connect asynchronous TTY compatible computer terminals and measuring equipment in our factories and offices (and within cities between offices) using the then state ministry of PTT owned copper phone-wires. It was faster (19.200 bps), less expensive and had a better electric separation (preventing ground loops and lightning damage). My novel approach was to use optocouplers instead of transformers to get electrical de-coupling of the sometimes long and interference (lightning etc.) prone copper wires on factory plants. Price we payed was 2 separate power units. Another success was that I did get it through the PTT approval process which allowed it to be used on PTT owned inhouse and local unloaded (not-pupinized) twisted pairs. It has [ PTT Toelatingsnummer 770502/TG1 ] **). Nowadays PABX phonewires are property of the owner of the private property and you have to lease local lines from KPN, for instance for ADSL.

Tillegraaf blogAbout 50.000 where manufactured under licence by Enraf-Nonius and sold by Vosko Networking BV, in Germany and the Netherlands. In Germany Deutsche  Telecom (FTZ) *) forced us to put a circuit in to prevent it from operating at faster than 4800 bits/second on Deutsche Bundespost (now Deutsche Telekom [DT]) in-house and local phone wires (2 copper twisted pairs). This photo shows the prototype with the extra “Bremms Schaltungs” peed cut-off board on top.

Tillegraag Duitsland

I also invented about 1977 the “Plector(r)” multiplexer, sold by Vosko too, which could connect 8 asynchronous computer terminals (TTY compatible with ASCII 8 bit start-stop characters) over one Tillegraaf(r) line. It implemented 8 UART’s to synchonize the character streams into 1 fast UART that functioned as parallel to serial converter.

Plector 1 blog

plector 2 blog

These devices did transport more data in those days than all the other local and wide area data networks of companies on PTT lines in The Netherlands added together.

Biggest incentive to develop the Tillegraaf was that it saved approx. 2000 Euro’s per terminal (most of them Digital Equipment DEC VT100’s or HP minicomputer terminals) connected compared to local links using the very expensive line drivers sold by Philips-Sematrans. Since the AKZO company (now AKZO Nobel BV) had a policy of not paying inventors in their laboratories extra for inventions for which they where hired in the first place, I put my name in: TILLegraaf. And I arranged that the royalties came in to the department account of my boss, which gave me extra freedom to explore things I considered important. I still do.

ir. Jaap van Till, theConnectivist

*) It took me about a year of my life to get the so called “FTZ Nummer Genehmigung” for it. The Fernmelde Technisches Central Ambt in Munich had set up a neat Franz Kafka construction for me. They told me that for inhouse copper wires from Bundespost or others we formally needed no Bundespost approval, while knowing quite well that no German would even dream of connecting any device to a “telephone line” without a FTZ number on it. After some mental arm wrestling I however did get the FTZ number, but they took revenge by insisting that in Germany on Bundespost kabels the jumper on the “Brems Schaltung” must be set to prevent links going too fast. I am not sure it was bacause no German manufactured baseband modem could work as fast as the Tillegraaf or that the higher speeds could not be wiretapped and listened in to with their equipment at the then dazzling speeds of 9600 bps or 19.2 Kbps 🙂

**) TG1 refered to PTT Dept of TeleGrafie (distance writing) which performed admission test for modems on the Netherlands Telephony network. Hence the name TilleGraaf . The rumor that I put GRAAF in because of my ambition to be upgraded by the King from baron to graaf van Till is false.

The Tillegraaf contained another trick, added by mr. Korzilius of our Arnhem laboratory: resistors on the twisted pair lines. In case one of the 4 wires broke or was cut the input of the receiver would not produce a flood of random bits into the connected computer, but would be jerked sideways to a zero voltage position. This is why TG1 admitted our apparatus and rejected other designs, by Hoogovens and by PTT itself, which where entered about at the same time. Yes the devil is in the details.

Advertisements

About broodjejaap

See ABOUT on TheConnectivist.wordpress.com
This entry was posted in Uncategorized. Bookmark the permalink.

8 Responses to My Inventions: the TILLEGRAAF linedriver and PLECTOR asynchronous multiplexer.

  1. Stofwolk says:

    Sweet memories, isn’t it?
    Homework:
    Find the SERIOUS typo in the text!

  2. kwalitisme says:

    It looks like the ‘r’ is missing on Jaap’s keyboard 😉 But nevertheless, great history. Too technical for most people I assume, who knows knowadays what V.24, UART is, or the difference between asynchronous and synchronous?
    Maybe it’s time for the Tillegraaf-IIF. In which the electrical components are replaced by fiber optic switching fabrics, with dense Wave Multiplexing, so existing fiberpairs can be used to increase bandwith to 10 Gbps Ethernet in stead of the ATM based 1 Gbps channels which are provided at high costs. So at last organizations can get rid of their internal systems and switch to cloud computing. 🙂

  3. kwalitisme says:

    Reblogged this on kwalitisme and commented:
    It looks like the ‘r’ is missing on Jaap’s keyboard 😉 But nevertheless, great history. Too technical for most people I assume, who knows knowadays what V.24, UART is, or the difference between asynchronous and synchronous?
    Maybe it’s time for the Tillegraaf-IIF. In which the electrical components are replaced by fiber optic switching fabrics, with dense Wave Multiplexing, so existing fiberpairs can be used to increase bandwith to 10 Gbps Ethernet in stead of the ATM based 1 Gbps channels which are provided at high costs. So at last organizations can get rid of their internal systems and switch to cloud computing. 🙂

  4. broodjejaap says:

    This was the original advertisement which appeared in “Computable” in 1977 if I remember it well.
    Yes, the R in Research was missing. Nobody is perfect you know, not even add-makers then.

  5. Pierre Lévy says:

    Great! I like inventors 😉

    • broodjejaap says:

      Pierre, I am lucky to have been able to experience the whole sequence from idea to getting approvals to product to distribution. Most important is to have IMAGINATION, which is a very scarce resource, indeed. Ted Nelson once said that most managers do not have enough imagination to imagine that some people can have it. Above the layers of wisdom, pragmatics, semantics, semiotics, syntax & patterns, symbols, signs and signals.

  6. It wasn’t that long ago really. Just an amazing story. Four decades ago nobody knew or could foresee what the Internet would be today. Or what a VDSL modem could do on a pair of wires. Netflix was a tin can with a 16mm film spool inside. Today we are looking at the histograms of our backhaul speeds and we can see when people come home, have supper or a coffeee, and en masse switch to Netflix and the likes. Makes you remember an old story of the electricity generator people on the Hemweg in Amsterdam keeping an eye on the TV program and switching on an extra generator a few minutes before a pause in the national soccer championships. Because everyone will get up to boil some water for coffee then. We don’t switch on extra generators now but we sure watch our backhaul capacity to stay on top of the demand.

    • broodjejaap says:

      Well, somthing has changed. Good Bandwidth is now the THIRD vital life condition (levensvoorwaarde) after food and safety. Real basic in the Maslow hierarchy of needs ( i did see a drawing with Wi-Fi and electric power as the bottom layer)

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s