Page 13 - DCAP507_SYSTEM_SOFTWARE

Unit 1: Introduction to System Software

 Instruction Set Notes
 new registers: LDB, STB, etc.
 floating-point arithmetic: ADDF, SUBF, MULF, DIVF
 register move: RMO
 register-register arithmetic: ADDR, SUBR, MULR, DIVR
 supervisor call: SVC
produces an interrupt for OS

 Input/Output
SIO, TIO, HIO: start, test, halt the operation of I/O device
 SIC/XE Instruction formats
 Bigger memory means an address cannot fit into a 15-bit field
Expand addressing capacity
 Use some form of relative addressing-> instruction
format 3

 Enlarge the address field to 20 bits-> instruction format 4
Additional instructions do not reference memory
 Instruction format 1 & 2
Self Assessment

Fill in the blanks:
6. Operating systems are directly related with the management of almost all of the
........................ of a computer system.
7. SIC points to ........................ which is a imaginary computer that has been intended to
comprise the hardware traits most frequently found on real machines, while averting
unusual and immaterial complexities.
8. The ........................ instruction tests whether the addressed device is prepared to send or
obtain a byte of data.

9. ........................ jump instructions JLT, JEQ, JGT test the setting of CC and jump accordingly.
10. Supervisor call ........................ produces an interrupt for OS.

1.3 Major Components of a Programming System

The Major Components of a programming system are explained as below:

1. Operating system
2. Language translators
(a) Compilers
(b) Interpreters

(c) Assemblers
(d) Preprocessors

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