IGCSE Computer Science Paper 1 Crossword: 4.1 Types of Software and Interrupts (Modules 409–418)
Name:
Date:
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Crossword
Read each clue and write the matching term in the grid. Numbers in brackets show the letters in each word.
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Across
- 2. A small program the CPU runs to deal with one particular interrupt. Each type of interrupt has its own ISR, kept in memory, and it is short so the CPU can quickly return to its task. Word 2 of: _________ _______ _______ (ISR) (7)
- 3. A full-mark answer uses the correct terms (system software, firmware, bootloader, ISR), gives points in the right order, and adds a ______ for each ______. Word 3 of: _____ and ______ (6)
- 4. The origin of the signal. From a device, like a key press or mouse move, it is a hardware ______. From a running program, like divide by zero or a memory clash, it is a software ______. Word 2 of: _________ ______ (6)
- 8. Word 3 of the term in 2 Across: _________ _______ _______ (ISR) (7)
- 10. Word 1 of the term in 4 Across: _________ ______ (9)
Down
- 1. The ordered steps: an interrupt is generated, the CPU finishes its cycle and detects it, saves its state, runs the ISR, restores its state, then resumes the original task. Word 3 of: _________ handling ________ (8)
- 5. What the ISR does depends on the event: it reads a key press, updates the pointer, shows an error or stops a faulty program. Then the CPU resumes the task it was running. Word 2 of: _________ _______ (7)
- 6. At the end of each fetch-decode-execute cycle the CPU checks for an interrupt signal. If none, it fetches the next instruction; if one, it switches to handling it first. Word 2 of: _________ _____ (5)
- 7. Each interrupt has a ______ level. The CPU handles the most urgent one first, so a power failure can pause the handling of a less urgent key press. Word 2 of: _________ ________ (8)
- 9. Word 1 of the term in 3 Across: _____ and ______ (5)
Answer Key
IGCSE Computer Science Paper 1 · Modules 409–418
1S
2S
E
R
V
I
C
E
Q
U
E
3R
E
A
S
O
N
C
4S
5O
U
R
6C
E
7P
U
H
8R
O
U
T
I
N
E
9P
I
C
C
O
O
O
K
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R
M
N
10I
N
T
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R
R
U
P
T
T
Y
Across
2SERVICE — A small program the CPU runs to deal with one particular interrupt. Each type of interrupt has its own ISR, kept in memory, and it is short so the CPU can quickly return to its task. Word 2 of: _________ _______ _______ (ISR)
3REASON — A full-mark answer uses the correct terms (system software, firmware, bootloader, ISR), gives points in the right order, and adds a ______ for each ______. Word 3 of: _____ and ______
4SOURCE — The origin of the signal. From a device, like a key press or mouse move, it is a hardware ______. From a running program, like divide by zero or a memory clash, it is a software ______. Word 2 of: _________ ______
8ROUTINE — Word 3 of the term in 2 Across: _________ _______ _______ (ISR)
10INTERRUPT — Word 1 of the term in 4 Across: _________ ______
Down
1SEQUENCE — The ordered steps: an interrupt is generated, the CPU finishes its cycle and detects it, saves its state, runs the ISR, restores its state, then resumes the original task. Word 3 of: _________ handling ________
5OUTCOME — What the ISR does depends on the event: it reads a key press, updates the pointer, shows an error or stops a faulty program. Then the CPU resumes the task it was running. Word 2 of: _________ _______
6CHECK — At the end of each fetch-decode-execute cycle the CPU checks for an interrupt signal. If none, it fetches the next instruction; if one, it switches to handling it first. Word 2 of: _________ _____
7PRIORITY — Each interrupt has a ______ level. The CPU handles the most urgent one first, so a power failure can pause the handling of a less urgent key press. Word 2 of: _________ ________
9POINT — Word 1 of the term in 3 Across: _____ and ______