sincerely thanks for the first comments.
Still 2 questions :
1) I though to use a minimum of 512 Mb RAM to allow copy2ram (all the slax in memory) but I am afraid that using multitasking or many tabs with the browser will slow the pc.
2) I also use some times gimp to work and I am also afraid that 512 Mb RAM is to small (when copy2ram is used). Then I though to have a look to a motherboard with low power consumption with at least 1 Gb RAM. Do you know one could use SLAX without problem ?
I run such a system for about a month. Nice mother board is Intel D201GLY2 - reasonably fast celeron and less than 20W. The nice way is to use pico PSU + external adapter 220 V -> 12V - also fanless and super efficient. As for mobo - its wise to place slow fan with thermo switch or regulator near to coolers (they tend to overheat slowly ), but ~ 1000 rpm in my case is even more then is necessary.
I added adapter from CF card to IDE, did as told with SLAX zip file (do not forget to make it bootable!), struggled for a while with screen resolution - now it goes.
Have a luck!
I run slax 6.0.3 on an ALIX.1C board also and it works well. The downside is that the on-board 256MB RAM is not expandable so running from RAM is out of the question.
If you would consider purchasing a barebones system instead of just the motherboard, check out the 533MHz fanless system sold by the Damn Small Linux project at http://www.damnsmalllinux.org/store/Mini_ITX_Systems/533MHz_fanless_Mini_ITX_PC. I have one of these running Knoppix 5.1.1 from compact flash, but slax 6.0.3 runs fine on it also. It supports up to 1GB DDR memory. The DSL store sells a CF adapter that mounts on the 2.5" hard disk bracket and works with the 40/44 pin IDE cable supplied with the system. The ECS (Elite Group) C3CVM6 motherboard is not available separately as far as I can determine. I found the manual for it at http://www.idot.com.tw/en/downloads/MB-PC1000E1500E(C3VCM6)/UserManual.zip.
A friend and I have installed earler versions of slax (pre 6x) on a Soekris.
It has no video output, so was running init 3 (text based) and ran a serial connection to connect to it. Booted and ran from flash, Its purpose was a slackware based low power consumption router including wireless.
It was redic fast for its purpose, but took a bit of configuration to get it going.
The one we ran was close to this configuration. (128 ram)
233 to 266 Mhz NSC SC1100 single chip processor
32-256 Mbyte SDRAM, soldered on board
4 Mbit BIOS/BOOT Flash
CompactFLASH Type I/II socket
UltraDMA-33 interface with 44 pins connector for 2.5" Hard Drive
1-3 10/100 Mbit Ethernet ports, RJ-45
2 Serial ports, DB9 and 10 pins header
USB 1.1 interface
Power LED, Activity LED, Error LED
Mini-PCI type III socket. (t.ex for optional hardware encryption.)
PCI Slot, right angle 3.3V signaling only, dual PCI slot option planned.
12 bit general purpose I/O, 20 pins header
Temperature and voltage monitor
Board size 5.2" x 5.7"
Power using external power supply is 6-20V DC, max 15 Watt
Option for 5V supply using internal connector
Operating temperature 0-60 °C