ULN 2003 or 2803

[Jadams]

I know your have addressed this several times, but after reading through most of the post and refering to some documents suggested by Jon, I'm still a bit confused. 

When your using the AP-8 you must use the 2003, or the modified 2803.  Without the AP-8 use 2803.  Or can I use the 2003 all the time?

Thanks for the lessons.

[JonnyMac]

You could of course use OUT7 as an output to drive a valve, relay, etc,; in this case you would need the ULN2803.  If your prop using P7 as an input or communications channel to our serial accessories then you can use the ULN2003.