Has PalmOne, the hardware side of the original PDA developer, missed out as the world moves to connected organisers? Two years after it launched the Tungsten T series, it has finally announced an SD Wi-Fi card, but only for two of its PDAs - the Tungsten T3 and Zire 72. Earlier Tungsten and Zire models are not supported.

It had already offered Wi-Fi on the Tungsten C - but that has a thumb-keyboard, and they have been less of a hit in SMS-mad Europe than in the email and IM-obsessed US.

Earlier this year, the news that SanDisk had managed to get Wi-Fi working on a Palm Zire 71 refocused attention on Palm's inability to support Wi-Fi on its mainstream Tungsten T devices, and raised fresh questions over its suitability for enterprise applications.

The problems with the Tungsten T family lie both in its hardware and software. The hardware difficulties are to do with its SD slot, says Martin Croome, general manager of Socket Communications Europe, which produces SD Wi-Fi cards but decided earlier this year not to develop Palm drivers for them.

"The Palm platform provides several challenges that make it more difficult to get complex plug in accessories to function," he says. "These are not necessarily faults in the Palm units, just different design choices that in many cases lead to customer benefits in certain scenarios, just not in ours!

"Firstly, on many of the Palm units the power available both in overall charge and peak current is less. This can cause issues with plug in products that add an extra load.

"Secondly, the Palm SD implementations vary over different products. Palm was much earlier with SDIO [the expanded version of SD that supports I/O as well as memory] than the majority of Pocket PC vendors so this is to be expected."

On the software side, the main issue is the lack of a comms layer and of good multitasking in PalmOS v5, and while operating system developer PalmSource is addressing this with Cobalt (PalmOS v6), many of the serious users who need comms - and who would have been a natural part of Palm's constituency a few years ago - have moved to Microsoft Pocket PCs instead.

All these differences mean that driver software would probably need to be developed individually for each Tungsten model, Martin Croome adds.

Both of Palm's problems are surmountable, but not easily. The Tapwave Zodiac has an enhanced version of PalmOS 5.2 and sports two card slots, one of them SDIO-capable, although it still has no Wi-Fi drivers. And even though Sony is withdrawing from the PDA market outside Japan, its Clie TH55 and TJ37 both have Wi-Fi built in, alongside another enhanced PalmOS 5.2 version.

The result is that anyone who needs a small device to pick up email in a cafe, scan the airwaves for rogue access points on the go, or use the wireless LAN to check some figures while in the office meeting room, will almost certainly be using a Pocket PC.

PalmOne wants to fix this, and with SD Wi-Fi suppliers such as SanDisk and Socket unwilling or unable to develop Tungsten drivers, it has taken on the job itself. Rick Hartwig, its head of European product marketing, says that this has been a complex task but that the Palm-branded SD Wi-Fi card with drivers should finally reach the shops in September.

There are also persistent rumours of a Tungsten T4, which would have Wi-Fi built in as well as Bluetooth. Some of the rumours suggest that it will be the 54Mbit/sec 802.11g version of Wi-Fi too, now that companies such as Broadcom and Atheros have low powered single-chip 11g solutions. However, for now they remain just that: rumours.

In the meantime, it is possible to connect a Tungsten T-series device to a LAN via a Bluetooth-capable PC and connection sharing software; it is not a trivial task though, nor is it as seamless as connecting a PC or Pocket PC to a Wi-Fi hotspot.