This page describes my experience with the Digital HiNote Ultra ct475, running Debian/GNU linux. I bought it second hand and it came with win95 installed. The battery was absolutely dead. The backlight is a bit dim. You can se and feel the laptop has been used, but it is in relatively good condition.
Installing Debian 2.2 - Potato on this laptop was straightforward. I just followed the debian installation instructions. Windows was installed when I got it. Using fips I made a 200 mb partition for windows and the rest for linux. In windows I downloaded the base system files needed for the installation of debian. Booted from floppy disks, installed the base system and the rest via network. No problems here.
Finishing the installation I tried to set up X (version 3.3.6) using XF86Setup. The c&t chip is supported by the SVGA server and the lcd monitor can use the default 640x480@60hz. It runs 16 bit colours. Can't get it to work with 24 bit (does in windows), but I haven't put much effort in trying, since 16 bit is for me the best trade off between number of colours and graphics-speed. I used XF86Setup but after a while the mouse 'freezes' and locks everything. Sometimes at once and sometimes after 10 minutes. Tried do disable gpm and used different mouse settings, but nothing worked. Searching the net I found this realizing there was problems with never kernels and this laptop. My solution was to use an earlier kernel 2.0.38 insted off 2.2.17 that came with debian potato. And that did it. I was able to run X without problems.
But with the new kernel the pcmcia modules didn't work since they were compiled for the 2.2.17 kernel and 'Potato' did not come with any precompiled pcmcia modules for the 2.0.38 kernel. So I booted the 2.2.17 kernel again (to get the network working) and browsed the web trying to find a debian package with precompiled pcmcia modules for 2.0.38 kernel. I could off course have compiled it myself, but at that time - compiling a new kernel and modules was far beyond my reach. I did find a package in the old debian archive (in slink) and installing it did cause som dependency problems so I just unpacked the archive manually and moved the modules to the appropiate places. Probably not the 'correct' method but it worked for me. Many months later I made my own kernel and modules with the make-kpkg in debian.
The 2.0.38 kernel works great, but I'd like to 'upgrade' to a 2.2 kernel (or 2.4) mainly because then I can run noflushd and spin down the harddrive more effectively than with hdparm.
So far the cd-rom drive does not work under Linux. The page over supported cards in the PCMCIA package do mention the "digital mobile media" - It doesn't work for me. Maybe one day I'll give it another try... The acces to the cd-rom drive is available through windows and is the reason I keep a small 200 mb windows partition.
It is possible to get the sound working under linux. The soundcard is soundblaster compatible. But this laptop makes an irritating whining sound when the speakers is on. And I usually prefer a silent computer, so I've disabled sound.
This page summarizes some of the options in the kernel-config to get sound working. Recording also works. Playback of wav-files is not correct. They are played to slow. But some fidling with settings etc, may correct that. I haven't tried to play mp3's or ogg files, but I doubt it being capable of that.
Standby and suspend and power off works...
I don't know if this works under linux. I don't use it so I haven't tried.
Another page describing the ct475 running linux.
Linux on laptops A great resource.
Here are a post on a mailinglist touching the problem with the keyboard and mouse 'freeze' in X. And for newer models a thread here.
This page (in Japanese) lists some options for compiling your own kernel - apm and sound. I had the Japanese part translated and it says that the mobile media module doesn't work...
Here you can find drivers for the Hinote's to use in Windows. You need some of these to get the sound and cd-rom - mobile media module - working in windows. You can also get a bios update there.
PWM is a lightweight windowmanager for X. Has good keyboard support and a small memory footprint. It's very recommended.