Tuesday, April 24, 2007

serial line and irq routing

Recently I have got a multi port serial card.
I need it to connect old notebook to pc. Notebook does not have ethernet or usb and I cannot find a pcmcia network card for its old slot in the vicinity. That is why serial line is a solution to setup a tcp/ip network via slip or ppp
The only difficulty was that my pc has only one serial port therefore if it is connected to the net via dial-up serial modem I cannot have neither internet nor just network on my notebook.
So, I've got a serial card and put it in pci slot of my pc. Once I did so I got problem with irqs.
Linux did hang when serial line (even the one on the motherboard) worked for some (short) time. I saw similar things before, on my nubus powermac with unstable kernel and buggy serial driver. That time I remembered Tannenbaum articles about micro kernel advantages.
To solve problem I changed irq settings in bios, disabled m/b serial port, recompiled kernel, tried to put card in other pci slot... and even read serial how-to.
After all I decided to install minix. Yes, it does not have 64 bit port but at least it is a good time and reason to play with it and get experience.
Before reboot and booting minix install cd I noticed interesting line in dmesg (why I didn't notice it earlier?) which suggested to use kernel option pci=routeirq to enable pci interrupts routing on acpi systems. That worked! now I am surfing web and even writing this note :)

Thursday, April 19, 2007


Kakraphoon is a planet mentioned in Duglas Adams's HitchHiker's Guide To The Galaxy. I intentionally use pixelization and limited number of colors to make pictures look like old vintage computer paintings :)
And I think that starting to draw is a very good idea! If you did not draw for many years, just start! It is funny and enjoyable!
What if not creativity will save you from being wheel in mega machine?