COS2621 Exam Notes.

COS2621 Exam Notes.

,COS2621 EXAM PAPER NOTES pages refer to PDF unless otherwise specified Nov2019
MAY/JUNE 2019 MCQ
1.1. [p396]
The flip- flop is a bi-stable device. It exists in one of two states and, in the absence of input, remains in that
state. Thus, the flip- flop can function as a 1-bit memory.
The flip- flop has two outputs, which are always the complements of each other. These are generally
labelled Q and Q́ .

1.2. [p416]
Arithmetic instructions provide computational capabilities for processing numeric data.

1.3. [not in book]
NASM is an ASSEMBLER while DEBUG is a UTILITY TO ASSEMBLE AND DEBUG PROGRAMS

1.4.




Running the program:
Step 1: Type this shit into a text file
Step 2: Save .txt file into .asm file
Step 3: run DOSBox
Step 4: mount c c:\c2621 (where my folder is)
Step 5: c: (moves you to that folder)
Step 6: as fileName (turns .asm to .lst)
Step 7:
for DEBUG
debug q14.com
type "u" to step through code

for running
q14.com

SOLUTION
1. 71h stored in position 101h, EFh stored in position 100h

, COS2621 EXAM PAPER NOTES pages refer to PDF unless otherwise specified Nov2019
Okay so it will be stored as follows:

dw 0x71EF
71 is stored in location 101h
EF is stored in location 100h
(since org 0x100)

This would make NASM little-endian since ...