This material is essentially Chapter 9 of the book Software Development in Pascal by
Sartaj Sahni, NSPAN Printing and Publishing, 1993. It is reproduced here with permission
of the publisher.
This the specification of the Enterprise JavaBeansTM architecture.The Enterprise JavaBeans
architecture is a component architecture for the development and deployment of componentbased
distributed business applications. Applications written using the Enterprise JavaBeans
architecture are scalable, transactional, and multi-user secure. These applications may be written
once, and then deployed on any server platform that supports the Enterprise JavaBeans
specification.
內容如下：
1.The history of the computerized database
2.SQL Data Statements--those used to create, manipulate, and retrieve data stored in your database example statements include select, update, insert, and delete
3.SQL Schema Statements--those used to create database objects, such as tables, indexes, and constraints
4.How data sets can interact with queries
5.The importance of subqueries
6.Data conversion and manipulation via SQL s built-in functions
7.How conditional logic can be used in Data Statements
In case you haven t realized it, building computer systems is hard. As the complexity of the system gets greater, the task of building the software gets exponentially harder. As in any profession, we can progress only by learning, both from our mistakes and from our successes. This book represents some of this learning written in a form that I hope will help you to learn these lessons quicker than I did, or to communicate to others more effectively than I did before I boiled these patterns down.
This firmware translates a PS/2 mouse to a USB mouse. The translator
firmware is entirely interrupt driven (with the exception of sending the
data via USB to the host.) An interrupt is generated when the PS/2 start
bit is received, at which time the firmware will begin its receive routine.
In addition to this interrupt, every 168ms a timer overflow interrupts the
main program and implements one state of the mouse state machine. This
state machine handles sending bytes to and translating bytes received from
the PS/2 mouse automatically. All of this is done in the background while
the main program runs in the foreground. The only operation that the main
program implements is sending mouse data to the PC via USB.
lwIP is a small independent implementation of the TCP/IP protocol
suite that has been developed by Adam Dunkels at the Computer and
Networks Architectures (CNA) lab at the Swedish Institute of Computer
Science (SICS).
