It is apparent that a variety of external IDE devices can be used for enhanced data storage for the netBook. Cheap data storage for the netBook can be found by using many PCMCIA IDE devices. Iomega clik! drives (very cheap 40Mb disks that slot into a reader that sits in the pcmcia socket) are one approach. Another is to use a PCMCIA to IDE converter (ca US$40 on ebay) to connect a normal or laptop CDROM drive or normal (3.5") or laptop (2.5") hard disk to the PCMCIA socket. Some of these devices will power directly from the PCMCIA socket (laptop hard drives?), but most will need some form of power supply in order to work. So it appears that with a PCMCIA IDE card (of which there are several varieties), all manner of external IDE devices can be plugged in. These cards seem to frequently have an odd 36 pin arrangement that doesn't plug directly into the normal 40 or 44 pin IDE devices; an adapter or housing is needed for the IDE device.
WARNING: Some of these cards/devices will only work with an external power supply to drive them; the netBook does not provide sufficient power on its own to the device. Do not plug the card in with the external 5 V power supply attached to the pcmcia device when the netBook is not started up/powered up already. The external device will power up the netBook the wrong way and it will cause a hardware failure. In my case, it blew a small fuse that was fairly easily mended, but it could also burn out the netBook's 5V supply, etc. - your netBook will fail to boot! Nothing on the screen, etc. i.e., disaster. (Some lessons are learned the hard way.) The fuse is near the power plug insert on the netBook mainboard. It is a tiny clear plastic or glass item that might have letters on it (e.g., "FG"), with a thin copper (or gold) filament running through it. If blown, the filament will have a gap. One quick fix is to short the fuse by wrapping this item with a thin, very thin, wire; it is work in a tiny space to be sure. A more conservative fix is to replace the fuse; in my case I am so terrible at soldering that the conservative fix is to send the netBook in for servicing.
Once the netBook has started to boot, the externally-powered pcmcia card can be safely plugged in - don't forget and push the pcmcia card in before the netBook is powered up: tie a ribbon on your finger, etc.; DON'T FORGET!!
At this stage it is unclear which types of IDE devices will work and which won't. Experience is limited.
It is possible to run a e.g., many-GB IDE disk on the netBook. This allows, among other things, a complete development environment to be set up, independent of the CF card, and also allows large, efficient swap space to be used. In addition, such disks can be booted by the netBook as the root device. The PCMCIA slot will recognized as /dev/hda (rather than the CF), if there is a disk there at boot up. An external linux system on a disk plugged into the PCMCIA slot can replace the system on CF by just being there when the system boots.
Once such PCMCIA card that has been verified to work is the "i88990" PCMCIA to IDE adapter frequently advertised on e-bay these days (July 2005) for $42 after shipping (from Hong Kong, worldwide) They appear to be no-brand custom cards. It allows connection of 2.5" hdd, but also have an adapter to allow 3.5" drives to be connected. One netBook (which has a rev 10 motherboard) was able to power laptop hard disks and laptop cd/dvd drives without external power. The laptop cd drives can be connected by using the 3.5" connector, and an adapter on the drive to allow connection to standard power/ide (3.5") cables for use in a desktop. One can of course also use standard cd/dvd drives with a power supply unit.
Another card that has been verified to work is the "IBM Travelstar E" PC Card. This is a PCMCIA card and a housing for the 2.5" disk. The housing is nice and offers lots of padding for the hard drive. These apparently originally came with a hard drive in them; the one I bought had had the disk removed (easily opened and straightforward install to be sure, but not exactly user friendly either!). With the disk plugged in and placed in the housing this card and a 12 GB Travelstar hard disk were both recognized and worked fine - but only with an external 5 V, 1A power supply. The exterior connection on the housing is the same as for the Noteworthy CD ROM described below, but the two PC Cards did not seem to be interchangable.
With a linux system installed on the hard drive (e.g. Sargebook installed on /dev/hda2), the system will be recognized as /dev/hda at boot up if the card is present, and so the netBook's linux system will boot off the hard drive, even if a CF disk is present. I partitioned my hard drive with 5.5 GB for ordinary i386 SuSE linux on /dev/hda1 and 5.5 GB for SargeBook on /dev/hda2; the SargeBook system booted fine - 5 GB free disk space!.
The Port Noteworthy PCMCIA 24X CD-ROM (Targus, NW24XCD) works fine on the netbook, and I am sure that many other types will as well. The NW24XCD seems to sell on e-bay for US$10-40 (7/05). This particular device requires an external 5V, 1A power supply to run properly in the netBook (otherwise the CDROM just goes clickity-clack and no CDROM device is recognized; try leaving the CDROM drawer open when the PCMCIA card is plugged in if you lack the power supply and want to test it), and the kernel must be compiled with ide-cd and iso9660 support. Other than that, there is little to the configuration; this is mostly handled by pcmcia services. If you attach the CDROM and then put in a CD, you may have to load the ide-cd module by hand. Mount the CD with the usual "mount -t iso9660 /dev/hdc /mnt/disk". Don't forget to unmount the CD and stop PCMCIA services before unplugging the PCMCIA card or your system will crash. Finally, it is probably best not to have the CDROM plugged in a boot up time, or your system may fail to start - the CDROM will be identfied as /dev/hda (unless you wanted to boot a system off CDROM!).
Whether the netBook is capable of running a CD-Writer or DVD remains to be seen.