Đang chuẩn bị nút TẢI XUỐNG, xin hãy chờ
Tải xuống
Nó được sử dụng rộng rãi bởi vì đơn giản, dễ thực hiện, và tốc độ. • thuật toán đối xứng được chia thành các thuật toán mã hóa dòng và mật mã khối. • Dòng mật mã mã hóa bit của tin nhắn, một tại một | 6 Chapter 1 A Technical History of Apple s Operating Systems 1.1.2. Apple The Apple I had a life span of less than a year but its successor would live much longer. Wozniak soon began work on the Apple . Although based on the 6502 processor as well the Apple was introduced as an integrated computer it came completely assembled in a beige plastic case. The contents of the original Apple package included the following. An Apple P.C. Printed Circuit Board complete with specified RAM memory A D.C. power connector with cable A 2 speaker with cable A Preliminary manual Two demonstration cassette tapes Two 16-pin headers plugged into locations A72 and J14 on the Apple board Latter models varied in their configurations as well as bundled accessories. For example Apple computers with 16KB or more memory came with game paddles and the STARTREK game tape. The Apple provided a machine-level monitor. Depending on the Apple model resetting the computer could either leave the user in the monitor or could auto-start the ROM dropping the user in BASIC. Calling a specific subroutine3 from BASIC allowed access to the monitor. The monitor provided commands for tasks such as the following. Examining changing moving and verifying memory Performing cassette I O 2 The Apple s keyboard connector was a 16-pin IC socket at location A7 on the main circuit board whereas a 16-pin game I O connector was located at J14. 3 Typing CALL -151 at the BASIC prompt provided access to the monitor. Mac OS X Internals www.osxbook.com 7 Configuring the video mode Assembling disassembling running and debugging machine code Upon its release the Apple was the first personal computer to display color graphics. Apple provided special software to make use of the Apple s capabilities including its graphical prowess. For example the High-Resolution Operating Subroutines package provided graphical subroutines usable from both BASIC and machine language. Using these subroutines the programmer could initialize .
