pixelation problems I think

Thanks I'm feeling hopeful.

Okay my older iMac that is having issues has firewire has 1 TB hard drive and I have two options for other computers:

an old Macbook Pro that also has Firewire but only has 500 GB or

a new iMac with 1 TB on it and has USB ports and thunderbolt. My G Tech back up drive where I'm trying to put files on uses either Firewire or USB no thunderbolt option. Do I keep my G Tech external drive plugged into the dud machine and then just attach via Firewire or USB cable to the new iMac?

Is this old computer toast basically?

Thanks Niel. My sister had Super Duper on her laptop so working on a clone now. Can I just buy an external monitor to hook up to my old iMac instead of buying a whole new computer since I'm guessing this is just a pixel issue. I may bring it in but will find out what the cost will be to look at it. If I can just buy a external screen then I'll do that instead. It doesn't have to be a Mac screen either.

Thanks so basically I have to bring it in to find out what's wrong with it before deciding the next step?

Congrats on reaching level 10.

I see, isn't there a way to buy a external monitor cord to attach to my dud iMac and try using either old Macbook Pro or the new iMac as an external monitor and see if it works?

Thanks Niel,

Just wanted to update you since you were so helpful. I went and bought a thunderbolt to thunderbolt cable as the mini display on my older late 2009 iMac has a mini display port which is the same size as the new thunderbolt. The same port is also on the Macbook Pro 2010 and newer late 2012 iMac. Tried to connect the cable using the Macbook Pro and nothing happened even though I had the right keys pressed. Then tried it on the newer iMac late 2012 and still nothing happened. According to instructions in the link provided one of them should have worked. When I returned the cable to the store I found out I could bring my old iMac in and they would do a free diagnostic check to see what was wrong. I brought my computer in and the tech guy said everything checked out fine but when I described the flickering I'd been having on my screen and the circuit like pixels he noticed faint lines during the diagnostic and said he was 85% sure it was the video card or something to do with the logic board (can't remember exactly what he called it). He said either of those would cost $800 or more to repair. So I saved $40 I would have paid to get a repair guy to look at it. Now I'll just transfer all my data over to the new late 2012 iMac which I'll be posting a question about.