Process by which a Stargate may be successfully dialed to another world without the use of a D.H.D. or other dialing computer technology -- provided it has a sufficient power source. A user must take physical hold of the Stargate's inner track and rotate it to the appropriate chevrons in order to gain alignment and lock in the seven symbols of an address. This can only be achieved if there is enough power for the Stargate to release the lock on the inner track to allow it to move freely.
In this case it still requires a great deal of physical exertion to spin the inner track, though it is possible for one person to accomplish alone.
Manual dialing is useful if there is no D.H.D. or remote computer connected to the Stargate. It it likely that the newer Pegasus Galaxy Stargates cannot be dialed manually, as they do not utilize a moving inner track.
The Torment of Tantalus - Daniel reviews archive footage of early tests on the gate where engineers were forced to turn the gate manually.
Prisoners - With the aid of Linea's plant-like cold-fusion power source, SG-1 performs a manual dial to gate away from the Taldur prison.
The Fifth Race - With the D.H.D. locked in place, Teal'c attempts to perform a manual dial to escape a warming planet with a binary sun group.
Nemesis - Teal'c manually dials a planet to evacuate the Asgard ship Beliskner, which has been compromised by Replicators.
Stargate Origins - With no D.H.D. connected to Earth's Stargate in 1938, Brücke's men (and later Beal and Wasif) must manually dial the gate to travel to Abydos.