Alan Perry's Blog

Wednesday August 29, 2007

The joys of cardbus 1394 and the 4-pin connector

A couple months ago, I discovered that 1394 Cardbus adapters just work with Solaris. Well, at least, the cards that I have work with the notebook computers that I have.

Thinking about it, this makes sense. Cardbus is basically a PCI slot in a PCMCIA form factor. And, like most 1394 host adapters, most 1394 Cardbus adapters are based on 1394 OHCI compliant silicon and Solaris has a 1394 OHCI driver, hci1394.

The odd and really unexpected thing is that, in my experience, these 1394 Cardbus adapters have turned out to be more reliable than the built-in 1394 hardware (and/or the 6-to-4 pin adapters that I use).

The problem is the 4-pin 1394 connector. All of the x86/x64 notebook computers in my lab have 4-pin 1394 connectors. It takes up less real estate than the 6-pin connector and it removes the hassle of dealing with implementation of the 1394 power provider/supplier rules, so I can see why company's use it.

However, the 4-pin connector has two big problems. One is that it provides no power for bus-powered devices like IIDC cameras and some hard drives, so one has to connect the device to the computer through something like a powered hub (or the adapter that I use which gets 1394 power from any available USB connector). The other problem is that the 4-pin connector has features that contribute to it being an unreliable connector, such as fingers inside the connector can fatigue and break off and a shape and size that makes it hard to insert the cable into the connector (which can lead to damaged connectors).

This is not to say that there aren't problems using the 6-pin connector. I have a six-port 1394 hub develop four dead ports over time, a three-port 1394 Cardbus adapter develop a dead port in the last month and every MacBook (Titanium) and iMac that has entered my lab left my lab with dead 1394 ports (some had dead ports coming in and others developed them here).

However, aside from the one dead port on my three-port 1394 Cardbus adapter, they have been remarkably dependable. If you are having problems using Solaris with your notebook, I suggest trying a 1394 Cardbus adapter.

( Aug 29 2007, 10:15:35 PM PDT ) Permalink