SPICE 11/16

The spice circuit simulator creates circuits based on netlists and then will simulate all properties of that circuit. These properties can then be displayed in a graph and or measured using a measure statement. Spice will also let you make sub circuits for any part you want to make out of transistors. The hardest part about spice is remembering all of the parts to the measure statements, to the transistor statements, and any sub circuits. The way the statements are formatted makes it hard to visualize the circuit which makes it hard for me to understand what all is going on. Spice is mainly used to figure out propagation delays of a circuit and or rise and fall times of a specific part of a circuit. Spice allows you to measure basically any aspect of the circuit and change the width of transistors while logisim only deals with the logic. Logisim will run inputs through gates and gives you the output but will not let measure aspects of the gates. You use spice when you want to optimize a certain aspect of a gate or part of a circuit by modifying transistors.

Databases 11/16

In Google app engine databases work by using GQL to store or access elements of an entity. Entities may contain one or more properties which has a name and a specified data type. All properties are stored within an entity in the form of a table. Each entity is identified by its kind which is specified in the name of the class which creates the entity and a key which is unique. The Google App Engine datastores do not update instantaneously so accessing an element which was just entered into the datawstore can result in problems. The GQL syntax which is very similar to SQL is used to retrieve entities or keys from the datastore.