Hi All,

I've used the 7805 to power my projects as well. It does have the input and output caps as Henk van den Broek talked about. I have experienced a noise problem if I power that with my homebrewed 12V power supply. Simply hooking up a rechargeable 12V battery solved that problem. I would suggest making sure your VSUP(12V) is regulated and clean of noise. Adding a 0.1uF cap as close to each chip from 5V to ground is good practice also. You also need to add the pull up or down resistors as you said. If there are alot of devices on the data line, an additional data latch may be necessary to permit the current draws.
For the reset circuit, you can simply have a 10K ohm resistor one side tied to 5V and the other tied to a 10uF cap with negative side grounded. Tie the reset of the cpu to the junction of the resistor and cap. Everytime the 5V is applied a reset will occur for a short time.
Check out www.lvr.com for a good book and circuits to use as I did.

TTYL,

Dave Kaleta