Can I use time maching to store data from two separate MACs
Certainly. Time Machine is designed to keep backups separate from one other.
Read more, courtesy of Apple Support Communities contributor Pondini: http://pondini.org/TM/4.html
Can we store the backups from both computers on one external hard drive or do we have to divide the hard drive? Understand Time Machine is not compatible with Airport Extreme?
I would partition the disk using Disk Utility. One partition for each Mac.
Time Machine requires either a locally mounted volume or Time Capsule.
Retrieving data ...