System Programming

Question 1

Firmware

Answer 1

Software that is programmed into the chips. Eg., BIOS

Question 2

SYSTEM SOFTWARE

Answer 2

Programs that supports the operations of the computer.
Implemented in either software or firmware which makes the hardware usable.
This help establishes the concept of the black box

Question 3

Difference between the System software and Application:

Answer 3

Machine Dependency- support the operation and use of the computer itself.

Question 4

Examples of System Software:

Answer 4

Text Editor
Compiler and assembler
Loader or Linker (former loads the program into the memory and the later combines all the object files and create a single executable file)
Macroprocessor
Utility Program

Question 5

Machine Dependent

Answer 5

Instruction Set; Instruction format; Addressing Mode; Assembly Language

Question 6

Machine Independent

Answer 6

General design; Two passes assembler

Question 7

SIC(Simplified Instructional Computer) comes in two forms:

Answer 7

Standard SIC
SIC/XE(Extra Equipment or Extra Expensive)

Question 8

Are both the forms of the SIC is upward compatible?

Answer 8

Yes

Question 9

Characterstics of the SIC:

Answer 9

Upward compatible
Memory== 8-bit bytes
Computer Memory == 32768 bytes (32KB)
5 registers, 24 bits in the length:->
A- 0- Accumulator
X- 1- Index register
L- 2- Linkage register(JSUB)
PC-8 - Program counter
SW-9 - Status word(Condition Code)

Question 10

Data Format of the SIC Machine Architecture:

Answer 10

Integers == 24-bit binary number
No floating point representations
2’s complement == -ve numbers
Charcaters == 8-bit ASCII codes

Question 11

Instruction Cycle:

Answer 11

Fetch Cycle
Execution Cycle

Question 12

Instruction Format in the SIC

Answer 12

24-bit form
flag bit x == indexed addressing mode

Question 13

Two modes of addressing in SIC

Answer 13

Direct: x=0: TA= address
Indirect: x=1: TA= x +address

Question 14

Instruction Set:

Answer 14

Format 3, load and stores registers, integer arithmetic proportions, COMP, Conditional jump instructions, JSUB returns to the subroutine placing the return address in register L, RSUB returns by jump to the address contained in the register L

Question 15

I/O in the SIC:

Answer 15

performed by transferring 1 byte at the time to or from the rightmost 8 bits of register A.
Each device is assigned a unique 8-bit code as an operand.
Test Device: Tests whether the addressed device is ready to send or receive,
< - ready = not ready

RD & WD

Question 16

SIC/XE Machine Architecture:

Answer 16

1 MB in memory
3 reg: B- 3, S-4, T-5
1 additional reg: F-6 (48 bits)

Question 17

Data format in the SIC/XE:

Answer 17

Integer: 24-bit
48-bit floating point values
exponent: 0-2047
f*2^(e-1024)
0: set all bits to 0

Question 18

Instruction formats in the SIC/XE

Answer 18

Relative addressing (format 3: e=0)
Extend the address to 20 bits(format 4: e=1)
no reference to memory at all: (format 1 and format 2)

Question 19

Addressing modes in the SIC/XE:

Answer 19

n i x b p e
Simple: n=0, i=0 or n=1, i=1
Immediate: n=0, i=1, TA=Valus
Indirect: n=1, i=0, TA=(Operand)
Base relative: b=1, p=0 TA=(B)+disp
0<=disp<=4095
PC relative: b-0, p=1 TA=(PC)+disp
-2048<= disp <= 2047
Direct: b=0, p=0 TA=disp
Index: x=1 TAnew=TAold +(x)
Index +base relative: x=1,b=1,p=0 TA=(B) +disp +(X)
Index +PC relative
Index + Direct: x=1,b=0,p=0
Fromat 4: e=1

Question 20

Instruction Set in the SIC/XE:

Answer 20

Format 1,2,3, or 4
Load and store registers (LDB, STB)
Floating point arithmetic operations(ADDF<SUBF<MULF<DIVF)
Register-to-register aruthmetic operations(ADDR<SUBR<MULR<DIVR)
A special supervisor instruction(SVC)

Question 21

I/O in SIC/XE

Answer 21

1 byte at the time
TD
RD
WD
SIO,TIO,HIO: start, test and halt

Question 22

Traditional CISC Machines:

Answer 22

CISC do all the loading through a single instruction.
Different Instruction formats and lengths.
Many different addressing modes.
EG., VAX or PDP-11 from DEC and Intel x86 family

Question 23

RISC Machines:

Answer 23

Standard and fixed instruction format
single cycle execution of most instructions
memory access available for loading and storing instructions
other instructions are register to register operations
small number of machine instructions

large number of general purpose registers
small number of addressing modes

Question 24

Three RISC machines:

Answer 24

SPARC family, PowerPC family, Cray T3E