This document is a side effect of two other projects I worked out. First the Linux-Ecology-HOWTO: "The Ecology-HOWTO discusses ways Linux computers can be used as a mean to protect our environment, by using its features to save power or paper. Since it does not require big hardware, Linux may be used with old computers to make their life cycle longer. Games may be used in environmental education and software is available to simulate ecological processes." And second the Linux Mobile Guide - Installing, Maintaining and Tuning of Linux on Mobile Computers.
If you search a Linux port for 286 CPU look at ELKS(http://elks.sourceforge.net/) . If you like, you may also use Minix(http://www.cs.vu.nl/~ast/minix.html) one of the predecessors of Linux. Minix supports 8088 to 286 (and better) CPUs with as little as 640K memory.
Installation of ELKS on the Commodore C286-LT was pretty straightforward. I took the
binary ZIP image of ELKS 0.0.77 . Unpacked the file and
rawrite2 to build the boot and root floppy.
Put the boot floppy into
the drive. Started the laptop. Changed to root floppy.
Logged in as root without a password. Did
ls /bin and
vi. Started to edit c286lte.html, which is this file
Recently I changed to 0.0.79 and put ELKS on the hard disk. It works fine. I still boot from a floppy, but I will try to get around this, too.
When I have some more time I will describe the installation in more detail. Just some caveats:
Rev 1.3 390854-01 (PHOENIX 80286 ROM BIOS PLUS VERSION 3.10.00 - 11, partly from Award and Cirrus).
You get the BIOS setup by pressing <CTL><ALT><ESC>
The BIOS reports:
640K Base Memory, 00384k Extended
2.5" 20MB Conner CP-2024 (653 or maybe 635 cylinders , I got
different information, precomp: none, 2 heads, 32 sectors, automatic parking,
maybe the only hard disk with 8-Bit XT-Bus interface,
BIOS parameters for the hard disk are: number 2, cyl 615, heads 4, sect 17, pre 300 lz 615
The label on the power supply looks like this:
input 100-240V~50/60 Hz 1.0A output 16V --- 1.5A fuse T3.15A
From Andreas Beutling I have got this report in German. All errors from the translation to English are by me. Here is his report in German and some additions about updating the RAM(http://tuxmobil.de/c286lt_de.html).
"... this notebook is still complete and working fully. It has been slightly improved with a 500MB harddisk and a second serial port (selfmade) in the modem slot. Also the original power supply is available. For the almost equally equipped C386LT an original service manual is available.
About the power supply: This device is not a common power supply, it is a combined charge and power supply with an integrated, intelligent charge chipset. The notebook itself has nothing to do with charging the battery, this is done completely by the power supply. A long time ago I have dismanteled it completely, because I have supposed something broken. I could detect the following features: The battery will be only charged, if the notebook is powered off. During the charge time the charge LED at the power supply is on, after that is goes off. The charge LED at the notebook is always on, when the power supply is connected und supplies voltage - no matter whether charging or normal operation. The charge operation follows different steps. First the battery is charged with a very low currency (app. 30 mA), exactly for five minutes. Only than the real charging starts, with app. 250 mA. Every twenty seconds the chipset loads additional 250 mA, until after some minutes the maximum of 2,5 A is reached. With this currency the battery is charged until "battery full" is detected, the end of charging is probably detected via Delta-U.
The label on the box of the power supply is more or less covering the actual numbers, because they don't fit. The power supply can be easily replaced by a simple panel, which can supply the notebook (therefore 12V at > 500 mA is enough) and than delivers a limited currency (app. 15 V) for charging, but a charge currency control and finish panel would be better.
My machine take app. 500 mA, and therefore runs with one battery load almost four hours. But this time I have only reached after changing the original hard disk with a modern and less power taking 500 MB hard disk.
View to the slots in the plug of the machine, or to the soldering site of the plug, marked (notch) at the bottom:
8 7 6 5 4 3 2 1
Table of connectors:
1, 2 ground (GND) 3 contact of the main switch to ground (normal=off open), will be looked up by the power supply 4, 7 work currency normal usage (12-16 V, 1,5 A) 5, 8 charge currency battery (up to 18 V, 2,5 A) 6 ground, comes from the power supply into the logic of the notebook
Please note with selfmade in-built power panels, that the connector 5/8 isn't connected directly at battery-plus, there is a diode type ERD64M-004 in between. Also you should know, that the connector 4/7 is always connected with the battery currency, but reduced by an additional diode of the same type. This connector is connected from the main switch into the machine.
C64 & More(http://consignmentseller.com/software.html) offers replacement backlight bulbs, power supplies, manuals etc.
I have tried to install Minix v2.0.3(http://www.cs.vu.nl/pub/minix/2.0.3/) but with no success yet.
Just for fun I have also installed FreeDOS(http://www.freedos.org/). It worked out of the box.