Simplified Instructional Computer
Encyclopedia
The Simplified Instructional Computer (also abbreviated SIC) is a hypothetical computer
, that is used as a base to explain the operation of a real computer. It was stated that most real microprocessors have a complex instruction set and many subtleties to increase efficiency, that can be a distraction for students that are studying the essential and universal aspects of a microprocessor
(that are common to different designs). Hence this hypothetical computer is used to explain all the basic concepts of microprocessor design even though it is impossible to cover every aspect. The architecture of the SIC uses 3 byte integers, 5 registers and can access 215=32768 bytes of memory.
Integer values are stored in 2's complement format.The ASCII encoding scheme is used for characters. The SIC has two versions; a standard version SIC, and an extended version SIC/XE. The extended version has floating point numbers.
Computer
A computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem...
, that is used as a base to explain the operation of a real computer. It was stated that most real microprocessors have a complex instruction set and many subtleties to increase efficiency, that can be a distraction for students that are studying the essential and universal aspects of a microprocessor
Microprocessor
A microprocessor incorporates the functions of a computer's central processing unit on a single integrated circuit, or at most a few integrated circuits. It is a multipurpose, programmable device that accepts digital data as input, processes it according to instructions stored in its memory, and...
(that are common to different designs). Hence this hypothetical computer is used to explain all the basic concepts of microprocessor design even though it is impossible to cover every aspect. The architecture of the SIC uses 3 byte integers, 5 registers and can access 215=32768 bytes of memory.
The five registers
- A register (accumulator): This is the three-byte register that is used for arithmetic operations.
- X register (index): The index register can operate in two modes, direct and indexed.
- SW register (status word)
- PC register (program counter)it contains the address of next instruction to be fetched for execution.
- L register (linkage): This register is used for subroutine jumps.
Integer values are stored in 2's complement format.The ASCII encoding scheme is used for characters. The SIC has two versions; a standard version SIC, and an extended version SIC/XE. The extended version has floating point numbers.
See also
- ComputerComputerA computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem...
- MIXMIXMIX is a hypothetical computer used in Donald Knuth's monograph, The Art of Computer Programming . MIX's model number is 1009, which was derived by combining the model numbers and names of several contemporaneous, commercial machines deemed significant by the author...
- System softwareSystem softwareSystem software is computer software designed to operate the computer hardware and to provide a platform for running application software.The most basic types of system software are:...
- Assembly languageAssembly languageAn assembly language is a low-level programming language for computers, microprocessors, microcontrollers, and other programmable devices. It implements a symbolic representation of the machine codes and other constants needed to program a given CPU architecture...
- Processor registerProcessor registerIn computer architecture, a processor register is a small amount of storage available as part of a CPU or other digital processor. Such registers are addressed by mechanisms other than main memory and can be accessed more quickly...
- Virtual machineVirtual machineA virtual machine is a "completely isolated guest operating system installation within a normal host operating system". Modern virtual machines are implemented with either software emulation or hardware virtualization or both together.-VM Definitions:A virtual machine is a software...
External links
- SICvm A Virtual Machine based on a Simplified Instructional Computer (SIC)