CDC slot

The CDC (Communications Daughter Card) slot is an internal expansion slot found in older 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

Overview

Cards listed here have a 40pin proprietary connector carrying signals for PCI, AC97 and USB.

Guessed size is 60×40mm and they show those two diagonal opposite screw holes.

List of available Communication Daughter Cards (with 40 pin connector)

• Ethernet Daughter Card (EDC) (a second 14pin connector goes to the RJ45 socket (I guess))
• Bluetooth Daughter Card (BDC) (additional 3 or 4 pin connector for what? one (or two) antenna connectors)
• Modem Daughter Card (MDC)
• ThinkPad 56K Modem (MDC-1.5) (an extra header (around 4 pins?) for RJ12 socket and something else)
• IBM Integrated 56K Modem (MDC-2)
• ThinkPad Modem (MDC-3.0, 56kbps HDA)
• IBM Integrated Bluetooth II with 56K Modem (BMDC) (extra header and antenna connector)
• IBM Integrated Bluetooth III with 56K Modem (BMDC-2)
• IBM Integrated Bluetooth IV with 56K Modem (BMDC-3)

See also

• Bluetooth Daughter Card (14 pins)

Photos (click to see full size)

CDC in a ThinkPad T43-2686

analog modem 56k at cdc

Models featuring this Technology

• ThinkPad A30, A30p, A31, A31p
• ThinkPad Template:Edge Series
• 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, W530, W540, W700, W700ds, W701, W701ds
• ThinkPad X22, X23, X24, X30, X31, X32, X40, X41, X41 Tablet, X60, X60s, X60 Tablet, X61, X61s, X61 Tablet, X300, X301
• ThinkPad Z60m, Z60t, Z61e, Z61m, Z61p, Z61t