Tech Flashback: Maestro Woomera (W56ERSP) 56k V.90 Modem

It’s pretty rare, but sometimes, your wishes get answered. Sometimes … just sometimes, you wish for something, it turns up on eBay … and nobody else bids for it and you end up snagging a bargain.

After the slight disappointment of finding the new Maestro Woomera seemed to be a slightly less sophisticated device as compared to what I knew about the original Maestro Woomera … a real original Woomera turns up for sale.

I couldn’t resist owning a modem which could be the best in the world even if largely irrelevant by today’s standards. Knowing what’s inside would really satisfy the curiosities brewing for over a decade.



This Woomera had lived a full life. It was a little dusty, and it had quite a bit of use as I was told. The box was included, but it was somewhat crunched. It’s nice to see the original packaging had a very Australian theme to it, and a retail orientation compared to the second generation unit.


A full list of benefits are shown on the rear – a massive five year warranty, LCD display, dual-standard K56flex and V.90 support, and eight line impedances (that’s twice as many as the second generation Woomera). Some digging around seems to suggest an internal version of the Woomera was made, but only with four line impedances.


This particular version was apparently the “CD Version” – which means that there probably was a floppy-disk version as well. Their marketing catch of “Maestro’s exclusive technology gives your internet F1 acceleration” seems a little over-the-top … and downright funny when compared to modern connectivity methods.

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The other sides of the box are mostly stock-photography, but it’s interesting to note that the modems were apparently manufactured in Australia. Very few electronics, by that stage, were manufactured here mainly as most of the component industries had already closed down and Australian labour is not known for being competitive. The contact details point to an address in Sutton, likely one of their offices, although their other documentation does still have the Bywong address as well.


Inside, we have the modem itself. The shell is exactly the same shape and size, but the plastic has a nice yellowing to it, making it a very time appropriate beige.


The design of the front has a mostly black-and-gold design, with a small hole for a microphone. This means this edition was a speakerphone capable voice modem.


This is confirmed with examination of the side near the power switch – it has jacks for headphone and microphone.


The rear ports are still somewhat haphazardly placed, although with some gaps. One of the screw-in sockets on the DB-25 connector was replaced since it was missing – likely taken out when the serial cable was removed, as the other was very loose and needed a good tighten.


The underside says this modem was dated 28th November 2003, making it 12 years old.

2016031621352726 2016031621352727It was supplied with an Adaptex branded 9v DC 600mA power supply that had the cable exiting from the top. As this was a used purchase, it was missing the serial cable, phone cable and CD containing full manual and BVRP phone tools.

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The modem did, however, have its quick start guide. The LCD display seems to be somewhat less sophisticated compared to the second generation Woomera, and the initialization string seems to reset to factory defaults (&F),  set tone dialling (T, although I suspect it is default anyway), set the modem to hang up on DTR drop (&D2, which is the default normally), set the data transmit attenuation to -14dB (S91=14) and set single-line connect message with additional information (\V1) which seems to be an odd thing to do every time you initialize the modem. Most of these settings are remembered (S91 is automatically saved, other preferences could be written to factory default/preset settings with &W&W1).

Even though many people swore by the voodoo of initialization strings for modems, the majority of them (possibly those excluding AT+MS (Rockwell) and AT-V90 (Lucent) settings) did nothing particularly interesting or even necessary. The most they really did was speed up your DTMF dialling, possibly increase the length of the loss of carrier timer to try and hang in a little longer when retraining, but that’s mostly it.


I couldn’t resist taking it apart any longer – and since I knew how to do it, I went straight in for it. Sadly, this unit didn’t quite survive unscathed – I managed to break two clips in the process. Part of the reason is that plastic becomes brittle over time and instead of the clips flexing to unbuckle, they like to snap. Oh well. At least it’s not as bad as some USR modems I’ve had my hands on – the case literally turns into small pellets as you start to handle it, and eventually, you just use it “bare PCB”.


My first reaction was an instinctive they don’t make ’em like they used to. They decided to shield the whole thing in a paper-and-foil box to shield the modem from external RF influences and possibly even to keep any generated interference in. After all, if you’re in a rural area, there’s a good chance you’ve got a weak AM radio signal, and electronic hash noise often likes to spoil it. Quite thoughtfully, there are holes for the speaker and a nice hole where the linear regulator’s heatsink is, just so it can keep a little cooler.


The front LCD is the same sort of LCD – an HD44780-compatible unit made by Truly.


Underneath its skin, we can see the modem is model ME120, with a date of 7th October 2003. The PCB is a revision B, and it seems quite nicely laid out in an opposite way of the 2nd generation Woomera – namely the line DAA is all on the right, and the logic stuff is on the left. Some dual-footprinting can be seen here – the line hybrid transformer here is an ABW ENG unit, although a different unit could probably be used (to the right). Two Omron relays are used to handle the line – and ferrite beads and MOVs abound.

The impedance matching circuitry is just under the line hybrid and is made of a Maxim MAX4581 8-channel multiplexer used as a switch. The resistors and capacitors below set the impedance – there are some unoccupied positions and J4 which is marked complex or 600 ohm, suggesting there may have been some that were field alterable.

A nice and large speaker is used, instead of the tinny little buzzer on the new Woomera, and it gives an overall better sound as to what is happening on the line.

While the Woomera had legendary status, a solid contender was always the Netcomm Roadster II Ultra SVD modems – they were often praised. The reason is quite clear now that I’ve opened one of these – both use the same RP56D/SP chipset from Conexant (formerly Rockwell). As a result, aside from the line-matching goodness and LCD display on this unit, both modems pretty much have the same brain and their firmware is likely to be substantially similar.


The underside has some QC labels with a similar signature to the one seen on the second generation Woomera.

In Use

The modem supports a serial baud rate of 230400bps, as advertised, and as some of the other modems using the same chipset also achieve. When actually on a data call, it sounds pretty much identical to my Netcomm Roadster II Ultra SVD – it even has the same annoying tendency to not aggressively try for V.90 on my VoIP simulated phone-line environment which has been optimized for data calling. Strangely, the second generation Woomera is so aggressive, it achieves 50667 bps connects where this one stubbornly decides to stick with 31200bps V.34 most of the time. A slight disappointment if I say so myself.

The modem supports the same AT&V1 statistics as that on the second generation Woomera, but the Maestro specific AT commands are different. The manual doesn’t seem to be linked, but thanks to the Internet Archive, I managed to find a link which was still active on the current server and get a copy and find commands to alter the display and clear the call database, but there doesn’t seem to be a command to display it like the new Woomera.

The display is somewhat different. On powering up, it does a self-test and shows its firmware.


Then it sits at this screen, idle, ready for use. The lower line indicates that intelligent line impedance matching is turned on.


When making a call, the screen is frantic with action.

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The signal quality figure can be incorrect at initial connection and no attempt to “mute” the display is taken. The display then cycles to show the impedance network in use.

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I haven’t seen it try any other networks except maybe #2 but I didn’t take a photo of it. Although they exist, so I suspect maybe there is some intelligence beyond just trial-and-error backed by statistical analysis. After many calls, it can show “LOCK” next to the network indicating that the modem has decided which network is best.

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The display then returns to displaying the signal quality and line level in a loop. The lack of aggressive attempts at V.90 seems to allow for additional stability, but sub-optimal speed, which is a little annoying. Part of the reason may be the transmit attenuation being set to -14dB by default, where some other modems seem to have -10dB as the norm. I tried setting different values, although the modem seems to ignore anything higher than -12dB and (as it was rather properly configured) refuses country region changes and certain commands which are improper for Australian phone-line usage (e.g. Bell mode ATB1).


At long last, I’ve got my hands on one of the supposedly best modems in the world, and I know what’s inside. I’ve seen it work, although, it is a little disappointing that it wasn’t more aggressive at negotiating V.90, as I know my VoIP system is quite up to the task as the new Woomera happily operates V.90 on it. Not quite the speed demon it seems (no reference to rival products intended), although I suppose where it really mattered on long country lines is where it would have made the most difference.

Origin of the name Woomera

According to Maestro’s manual, it states the following:

The woomera is an Aboriginal tool for launching spears into flight. The picture on the front cover of this manual is a woomera. A woomera acts as an accelerator, enabling the spear to travel up to three times further than a hand-thrown spear. The Woomera rocket range is located in a remote area of South Australia and provides a high tech environment for research and experimentation. Range facilities include launch sites, rocket preparation, communications, telemetry and tracking equipment.

The space-age technology of the Woomera Rocket Range, combined with the image of speed and distance achieved by the Aboriginal woomera, are well represented in our Woomera modem. The name “Woomera” was an appropriate choice for our all-Australian modem.

About lui_gough

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