what is a disc on chip? - beginner's question

[Alessio Sangalli]

Hi, this is not the first time I write but in the past months I was too
busy and I had no time to build a nice linuxbios-box!

However now I'm going to buy a pchips motheboard so I can start to
experiment.

I've read the useful guide on the web; however I have some doubts:

what about that disc on chip device: how much does it cost more or less?
Why can't we use a normal FLASH memory like the ones used to store a
standard BIOS? I can think those chips provide particular features, but
which ones exactly? Aren't common flash/eeprom chips much easier to find
and cheaper to buy? An external programmer could be needed (like for the
eproms of etherboot) but most people could have access to such a device.

Bye bye and thank you!
as

P.S. I've read just now that on the pchips motherboard for athlon cpus
the L2 cache is not working. Is it true? As the cache is on the
processor and not on the mainboard, I thought this wouldn't be a problem...