Note: Sharp has revamped their web site and apparently discontinued the Actius models discussed here. As I write this they have a not-very-useful Actius Ultralite page which will probably get filled in with new models at some point. So you may notice some "file not found" links to Sharp here. Apparently in some parts of the world you can get one of the followup models, the AX series (AX-10, AX-20, etc), but I haven't seen them available in the US.
I used to have (I had to give it back to OSU when I left) a Sharp Actius UltraLite PC-A280 that I just loved. Since I no longer have it, I'm afraid I can't answer any questions that aren't covered here. It's smaller (but thicker, of course) than a letter-size sheet of paper, about an inch thick, about 3 pounds, has a bright 11.3-inch 800x600 screen, and built-in 10/100Mbps ethernet. The shiny silver styling doesn't hurt either; combined with the size, it turns quite a few heads. I bought the machine for use in giving presentations and carrying around campus on consulting expeditions, and it was excellent for those uses and much more.
Sharp also released an A290 model whose main (only?) distinction over the A280 is a 1024x768 screen instead of 800x600 like mine, at the same 11.3-inch size. (800x600 can be cramped if you're not used to it, but it's not hard to adapt to.) The PC-A800 also looks interesting if you want a bit more in the main unit. Sharp's bright screens are probably the major things that distinguish their laptops from their competitors; once you've had such a bright screen (300:1 contrast ratio), it's really hard to go back to anything less.
The keyboard is smaller than standard and has a nonstandard arrangement for the arrow keys, not to mention requiring the use of the Fn key to get Home, End, PgUp, and PgDn, but I got used to it quickly. The keys are laid out logically, unlike some laptop layouts I've seen. Like most laptops these days, there is a square touchpad for use as a pointing device, with two buttons; this works fine as a PS/2 mouse. 3-button emulation works by pushing both buttons at once, but you can't just push a single finger on the edge where the two buttons meet, like you can on IBM Thinkpads (of course, those have the wonderful eraserhead pointer too). This makes middle-button functions difficult to access.
The PS/2 (keyboard/mouse), RS-232 serial, and parallel ports are on the external floppy unit, which wasn't a problem for me, and will be nearly irrelevant as Linux gains more USB support (there are two USB ports on the main unit). I only rarely needed to use the outboard ports, but I did carry the 1-pound floppy/port unit with me much of the time. (I did like that I didn't need to carry it to use the computer though.) The floppy/port module connects to a custom port on the right side of the computer; this port has a plastic cover (unlike the other covers, which are mostly rubber) that could pop off if you don't watch out (though it's easy to put back unless it breaks).
The monitor port and ethernet port are on the back of main unit, but
are both covered by the external battery when that is attached; that's
OK, because if you have a monitor and/or ethernet, you should also be
near a power outlet.
I highly recommend getting the 1-pound external battery, since the
internal one only lasts about an hour or so. With the external
battery you can get 5-6 hours of battery time. (I get five hours when
using the machine primarily for connecting to the net with a wireless
networking card.) Both the onboard battery and the external battery have
a little 4-LED bar graph indicator showing approximately how much
charge remains; the indicator comes on while charging or anytime you
push the little button next to it. Charging, of course, is done by
plugging the laptop into the AC adapter, which is pretty light and
small. However, after long periods of use the AC adapter can get a
little hot, particularly if it's not well-ventilated (e.g. tucked
beside you on the couch).
Don't bother with Sharp's cdrom drive, since it's overpriced and not Linux-compatible. I used a SCSI PCMCIA card connected to a SCSI CD-ROM drive on the rare occasions when I needed CD access. The built-in ethernet (and modem, after I got that working) is really convenient, and eliminates the need for two PCMCIA slots, although sticking an IEEE 802.11 wireless network card in the single PCMCIA slot can be really nice too. For the built-in ethernet to work with Linux 2.2, you need to turn off Plug'n'Play in the BIOS. I don't know if Linux 2.4 changes this.
The internal modem is a PCTel HSP software modem, so it requires some
extra work to make it work in Linux. But it can work!
I found a
Linux Winmodems page
and I've had some preliminary success with that, actually achieving
56k-class PPP connections. I relinked the driver for my 2.2.14 kernel
(by running "make" in the src directory), then copied the new pctel.o
file to /lib/modules/2.2.14/misc/. I added the following line to
/etc/conf.modules (or modules.conf on some systems):
alias char-major-62 pctel
Then I ran "depmod -a" and got a message about unresolved symbols in pctel.o, but after that I could access /dev/ttyS15 (which is created with "mknod /dev/ttyS15 c 62 79") and the module would automatically load. After that /dev/ttyS15 acts like any other 56k modem, except you don't get any dialing sounds from the speaker (at least I didn't when I tried it; I've been told that with later driver releases it works.)
Linux Laptops page
has a link to a
describing how Aaron Barth got Linux going on an
I used that page as a guide on my A280, except that I installed
which is based on Red Hat. I used
FIPS to make
Windows 98 use only 1GB of the 8GB disk.
Partition 4 was defined as a small "Thinkpad" partition, for
suspend-to-disk, and I left that alone when repartitioning.
as a boot selector/loader. I edited one line of /etc/inittab so that
when I hit control-alt-delete (and all apm abilities are enabled in
the kernel), the machine shuts itself off rather than rebooting:
ca::ctrlaltdel:/sbin/shutdown -t3 -h now
I conserved battery life by having my disk spin down if it hasn't been used in one minute (hdparm -S 12). However, this causes slow response while waiting for the disk to spin back up, and it is not as necessary to conserve power when running on AC power. apmd allows setting actions to happen when the power status changes, such as switching to AC power or switching to battery power. Red Hat (and distributions such as Mandrake that are based on Red Hat) allows hooking into this ability by adding a script in /etc/sysconfig/apm-scripts/ called apmcontinue. My version sets a 1-minute timeout when on battery power, and a 30-minute timeout when on AC power.
With an 800x600 LCD screen you normally have a choice in text mode:
you can have your text screen only use part of the physical screen,
or you can enable "stretching" in the BIOS configuration, resulting in
a full screen, but with ugly jaggy characters because the screen
size isn't an even multiple of the original font size. Beginning
with Linux 2.2, we have a better option. Using the Linux kernel's
VESA framebuffer mode and setting "vga=788" in /etc/lilo.conf, I
got an 800x600x64k framebuffer, which then results in a 100x37 text
screen. It also takes the XFree86 3.3.6
about a second less time to start up than the SVGA server I'd
otherwise use. However, with the FB server, KDE complains about no
power-saving (but I used GNOME instead). Also, I found that when
connecting to an external video projector I needed to disable the
framebuffer ("vga=0") and use the SVGA X server for things to work
correctly. With both servers, I used Aaron Barth's recommendation of
telling X that I have a
Cyber 9525 video controller (irrelevant in framebuffer mode) and
monitor with 50-70Hz vertical refresh, 32-53.7 horizontal sync. I
actually only use one modeline; the rest can be deleted if you always
use the laptop's 800x600 screen. Presumably the 1024x768 Modeline
listed below will work on the laptops with higher-resolution screens.
# 800x600 @ 60 Hz, 37.8 kHz hsync
Modeline "800x600" 40 800 840 968 1056 600 601 605 628 +hsync +vsync
# 1024x768 @ 60 Hz, 48.4 kHz hsync
Modeline "1024x768" 65 1024 1032 1176 1344 768 771 777 806 -hsync -vsync
I don't know how XFree86 4.x affects all this...
A lot of people looking for small laptops get Sonys, but then they have all sorts of problems getting sound and video to work correctly. I also think the Sharp looks much cooler than the Sonys do, and I know it runs cooler than at least the PIII-based VAIO that my co-worker bought. I just sit there smiling with my cool working Sharp running X and playing my (yes, legal) mp3's on the Sharp's ESS Solo-1 chip. For some reason RealPlayer plays things too fast, but the other sound applications I've tried work fine.
I never tried the machine's infrared abilities, but I have no reason to doubt that it would work.