Any way to change SATA boot order?

if I have two, or for that matter, 'n' SATA drives in a system, and one is bootable, the rest not, how come my GX620 optiplex/dell doesn't just go down the chain and boot anyway?
it seems [BIOS??] to assume only one SATA device in the overall boot scheme. SATA doesn't deal with master/slave stuff, right? its a marxist system....

 

Most Mobos will let you set boot sequence, as in CD, floppy, hard drive, etc. You will also find you can often change the overall structure should you have more than one HD, so that you can chose which is the bootable disk.
You need to set each item as bootable- if your boot list has Hard drive and nothing else it wont look anywhere else. Computers are stupid, and do EXACTLY what you tell them. Not their fault that the idiot is at Dell

 

Boot order on a Dell is typically F12 at start up.