U810 Flash

I now have the Transcend 32GB CF card as the main storage with OpenSuSE 11.0 on it - partitioned as 4GB root, 25GB /srv and 1GB swap (to allow suspend-to-disk). Install was relatively painless with the caveats already mentioned. Some things to note...

1. I plan to use an internal sacrificial USB flash disk (with any luck!) ultimately for swap and tmp space to keep the write load on the CF card down.
2. To simplify this I have created a tempfs for /tmp so temporary files are written to RAM and then swap - thus I only have to deal with moving swap to USB. To do this, add the following to /etc/fstab:
   
   none /tmp tmpfs size=1G,noatime 0 0
3. Symlink /var/tmp and /usr/tmp to /tmp (technically this might be a little suspect in terms of security but this is a personal laptop, not a server)
4. /var and /home might need some consideration as a whole but not right now
5. Partitions are ext2 with noatime and noacl to help keep flash activity low
6. As mentioned before, Transcend 133x CF seems to write at about the same speed as the Toshiba HDD and read around twice as fast. Certainly booting and return from hibernation are noticebly faster.
7. Power consumption drops quite usefully with the CF card - with the HDD I never saw less than 7000mW (based on KPowersave readins). Now I've seen under 6000mW (with WiFi off) and nearly 6 hours runtime.

I've been rooting round under the bottom panel with a view to fixing an internal USB connector for my sacrificial scratch flash. armed with a multimeter it appears that the second PCI-E connector is not powered up - some fuses are missing but the adjacent power planes are also unpowered. There is, no doubt, something like a regulator that requires a pull up/down to get the power planes energised.

Anyway, looking around elsewhere doesn't turn up a lot of options for voltage sources (I am restricting myself to what I can reach under the bottom panel without further dismantling). I am considering using the SD card power supply voltage since the contacts are easy to reach and Fujitsu has opted for the uppoer end of the SD voltage spec and given it 3.5V.

3.5V should power 3.3V nominal electronics just fine. Many USB devices take the 5V supply and regulate it down to 3.3V immediately. I can either bypass the regulator and run the devices slightly over nominal or hope the regulator can cope with a voltage differential that small (possibly undervolting slightly). Now I just need some nice fine wire...

More U810 thoughts

The U810/U1010 has pads for two Mini PCI-e slots underneath the bottom cover but most only have one in place. Looking at the dissection photos on the Internet it seems that there are no chips or support components missing - just the socket - so it should be feasible to solder a new one in - the pads are easy to reach and the pitch isn't too small.

Getting said socket isn't too easy though - RS Components has them scheduled for October. It looks like the exploding demand for eee PC's and the like has drained the world's supply of Mini PCI-e sonnectors - later eee's also come with only one of two possible sockets in place.

The other alternative, in the same vein as many eee PC mods, is to tack a USB socket in place of the PCI-e connector (using the USB lines that are available on the PCI-e pads). That would be a nice place to put a USB key as an SSD or maybe a TV tuner... Now I just need to find a nice point I can source 5V from - with all the eee PC hacking out there I'm surprised there hasn't been a bit of U810 activity in this area.

I have also got a Compact Flash to 1.8" ZIF convertor (off ebay) to try out using CF as an SSD alternative - slower but actually designed for low power consumption so may well benefit run-time. The first couple of CF cards I tried weren't recognised by the BIOS. To test that it wasn't the convertor I got hold of an Icy Dock USB caddy from Scan - obviously designed for displaced iPod drives! The cards worked fine in this mode - I suspect it is because most CF cards claim to be removable ATA devices and some BIOS's will only accept fixed devices. Transcend is one of the few manufacturers whose CF cards switch to "Fixed" mode when operating in IDE, rather than CF, mode so I'll get hold of one and try it. Sandisk, Kingston and Intuix are brands which do not - from experience. Under Linux you can use hdparm -i on a CF card to find out if it is Fixed or Removable mode.

Elisa 5.3 seems to be an awkward release to get up and running - I had to edit the source code (to bypass a "not implemented yet" error) to even get the main screen up so I'll park that for now until a later release.