Thinkpad Mini PCI wireless cards

Recent Thinkpads (at least the A30, A31, G40, R32, R40, R50, R51, T30, T40, T41, X30, X31, X40) have a list of wireless cards that they will boot with. Only Mini PCI cards are affected by this, so any PCMCIA, Cardbus, compact flash or USB device will work without problems. The set of cards that work is determined by the PCI vendor ID, product ID and (in at least one case) the subsystem ID. For more background, see here. IBM's version of reality is also discussed.

The implementation of this check is fairly simple. Each PCI device has a unique string describing the vendor and product. Many also have a "subsystem id", a further string which allows two slightly different variants of a product to be differentiated. The Thinkpad BIOS reads those numbers off the device in the mini PCI slot and checks them against an internal list. If they appear on the list, the machine boots. If they don't, the following message is displayed and the machine refuses to boot:

1802 Unauthorized network card is plugged in. Power off and remove the Mini PCI network card.

There are two ways to avoid this problem:

I've produced a table of the PCI IDs found in the X40 BIOS along with information about some other Thinkpads. You can find it here

Note that not all cards supported in earlier Thinkpads are supported in the X40, and presumably not all cards supported in the X40 are supported in earlier Thinkpads. This IBM page lists various wireless devices and which machines they will work in. Note that this list is not exhaustive. The Intel 2200 card is not listed as an X40 option despite being optionally sold with it, and the Lucent Orinoco is not listed at all. Also note that the IBM page specifies model names, but in at least one case (the Intel 2100) the standard part under that name will not work. The IBM version of the card has a different subsystem ID, and this is checked on boot. A standard Intel part will not work in an X40. I don't know if the same is true of earlier Thinkpads.

Most objectionable is that the only point at which this is mentioned is buried in a list of legal footnotes in only one of the pages describing the product. Elsewhere, IBM document the X40 as having a Mini PCI slot (the type III refers to the physical space requirements) with no mention of this restriction. The advertising is, at best, misleading.

Why this is objectionable

If Asus sold motherboards that were only compatible with Asus graphics cards, people would be less likely to buy Asus hardware. If they placed this information in a small footnote and simultaneously listed an AGP slot in the technical specifications, people who had purchased the hardware with the expectation that they could use their existing graphics card with the same chipset would be justifiably angry. The situation is directly analagous. IBM may feel that US law requires them to implement this restriction in the United States. However, failure to clearly advertise this restriction (especially given that most of the world is not covered by FCC regulations) is unacceptable.

Matthew Garrett
Last modified: Sat Apr 24 11:40:56 BST 2004