Question: Which types of memory cards does the DS-4000 support?

The DS-4000 is compatible, out of the box, with Standard and Type M xD-Picture Card media in capacities from 16 MB up to 512 MB. Newer firmware is available to add support for Type M and Type H cards up to 1 GB.

This model does not support Type M+ xD-Picture Card media or the 2 GB Type M card.

Firmware updates are available from and must be performed by an Olympus Professional Audio Products dealer.
Verification Source: Olympus Website