nick14, please do proove me wrong and produce some goods because this thread is stupid, if you had the ability to do this correctly, you should easily have the knowledge to answer these noob questions.
LOL so you got the CPU from a PC and just 'installed it'?
Sure you did..
I for one would like to see some pictures of your upgrade.
Upgrading to ANY different CPU is a real challenge, even the 1GHZ chips require modification to the board.
The 1.4GHZ, was a celeron type chip aswell if i remember correctly.
Both of which were mobile chips, so one from a PC is a big no no, for one thing its about twice the size of a mobile chip, have you even had the heatsink of your CPU and had a look?
The fact you said its got 256MB RAM does it for me.
Oh and incase you really want to see some work, heres a couple of shots i did while attempting a 1GHZ CPU upgrade a long time ago, still never did finish off the work and get it sorted.
As you can see, not really just something you can do at your dining room table and does indeed require GBA rework facilities.
EDIT: Kirky, yes you can indeed get some of the older Geforce cards and remove their RAM chips, if memory serves they are around the Geforce 2 time. 4x16MB chips.
And bomb_bloke, you don't need a special BIOS to run a different CPU providing the pin out of the CPU matched correctly to the motherboard, in such a case it wouldn't work.
