CDC slot

The CDC (Communications Daughter Card) slot is an internal expansion slot found in modern ThinkPads.

It is not meant for customer upgrades.
Different CDC slots exist for different functions and different form-factor cards, so you cannot just install any CDC adapter into a CDC slot.

The types of CDC cards you can use in your system is dependent on the BIOS. If you insert a Bluetooth IV with 56K Modem from an R52 system (for instance) and place it into an R51 system which only had the Modem Daughter Card, the system refuses to boot up and displays Invalid Daughter Card.

• Wikipedia article on CDC

CDC Adapters

• Ethernet Daughter Card (EDC)
• Bluetooth Daughter Card (BDC)
• ThinkPad Bluetooth with Enhanced Data Rate (BDC-2)
• ThinkPad Bluetooth with Enhanced Data Rate (BDC-2.1)
• Modem Daughter Card (MDC)
• ThinkPad 56K Modem (MDC-1.5)
• IBM Integrated 56K Modem (MDC-2)
• ThinkPad Modem (MDC-3.0, 56kbps HDA)
• IBM Integrated Bluetooth II with 56K Modem (BMDC)
• IBM Integrated Bluetooth III with 56K Modem (BMDC-2)
• IBM Integrated Bluetooth IV with 56K Modem (BMDC-3)

Photos (click to see full size)

CDC in a ThinkPad T43-2686

analog modem 56k at cdc

Linux support

The different cards appear as either PCI, AC97 or USB devices.

Models featuring this Technology

• ThinkPad A30, A30p, A31, A31p
• ThinkPad Edge 13", Edge 14", Edge 15"
• ThinkPad G40, G41
• ThinkPad R30, R31, R32, R40, R40e, R50, R50e, R50p, R51, R51e, R52, R60, R60e, R61, R61e, R61i, R400, R500
• ThinkPad S30, iSeries s31
• ThinkPad SL300, SL400, SL400c, SL410, SL500, SL500c, SL510
• ThinkPad T23, T30, T40, T40p, T41, T41p, T42, T42p, T43, T43p, T60, T60p, T61, T61p, T400, T400s, T410, T410i, T410s, T410si, T500, T510, T510i
• ThinkPad W500, W510, W520, W700, W700ds, W701, W701ds
• ThinkPad X22, X23, X24, X30, X31, X32, X40, X41, X41 Tablet, X60, X60s, X60 Tablet, X61, X61s, X61 Tablet, X200, X200s, X201, X201i, X201s, X201 Tablet, X300, X301
• ThinkPad Z60m, Z60t, Z61e, Z61m, Z61p, Z61t