2026年IGCSE计算机0478 Paper 1明日开考！机构老师给大家整理了IG计算机P1高频考点、答题技巧和模板，以及易错点，考前过一遍，帮你多拿10分，为你冲A*保驾护航！
IGCSE计算机P1考试规则
IGCSE计算机P1高频考点
1. Data representation
Number conversion:Binary → denary: add place values. Denary → binary: use 128,64,32,16,8,4,2,1. Hex ↔ binary: group into4 bits. 中文：十六进制每 1 位对应 4 位二进制。
Binary addition:Add from right to left. 1+1=10, 1+1+1=11. Overflow occurs when result needs more bits than available. 中文：8-bit 加法结果超过 8 位就是 overflow。
Logical shift:Left shift usually multiplies unsigned binary by 2 per position; right shift divides by 2 per position, but lost bitsare discarded. 中文：不要忘记补 0 与被移出位丢失。
Two’s complement:For negative numbers: invert bits and add 1. Most significant bit indicates sign in signed representation. 中文：最左边是符号位, 1 表示负数，0 表示正数；step1 先转为二进制，step2 翻转 0 和 1(符号位不变), step3 加一
Images: File size = width × height × colour depth. Higher resolution/colour depth increases file size. 中文：颜色深度 bit depth决定每个像素需要多少 bit。
Sound:File size = sample rate × sample resolution × duration × channels. Higher sample rate/resolution improves fidelity butincreases file size. 中文：采样率越高，声音越接近原声。
Character set:such as ASCII(7bits) or Unicode ,is a collection of characters and their corresponding binary values
2. Data transmission
Packets:Large files are split into packets; each packet may contain header information such as destination/source address,sequence number and error-check data. 中文：sequence number 用于重组顺序。
Serial vs parallel:Serial is reliable over long distances and uses fewer wires; parallel can be faster over short distances butsuffers from skew/crosstalk. 中文：长距离优先 serial。
Simplex / half-duplex / full-duplex:Simplex one-way only; half-duplex both ways but not at same time; full-duplex both wayssimultaneously. 中文：电话 full-duplex，对讲机 half-duplex。
Error detection:Parity checks add a parity bit; checksum uses calculated totals;ARQ requests re-transmission if errordetected.中文：error detection 不是 error correction，除非题目提到 re-transmission。
Parity check:A parity bit is a single bit added to a transmission that can be used to check for errors in the transmitteddata.Its value is calculated based on the transmitted data itself.
Encryption:Plaintext → ciphertext using key; symmetric uses same key; asymmetric uses public/private keys.中文：HTTPS 用加密保护传输数据。
3. Hardware
CPU cycle:Fetch instruction from memory, decode it in control unit, execute using ALU/registers, store result if needed. 中文：F-D-E 顺序要稳。
Registers:PC stores address of next instruction; MAR stores memory address; MDR stores data/instruction being transferred;ACC stores intermediate results. 中文：寄存器题要写“存什么”。
Performance:Clock speed, number of cores and cache size can improve performance, but software must be able to use them. 中文：不要绝对化“more cores always faster”。
Storage:RAM volatile and fast; ROM non-volatile; SSD has no moving parts and faster access; HDD cheaper per GB; optical isportable but slower. 中文：比较题写 feature + consequence。
Embedded systems:Dedicated computer built into a larger device, often with limited hardware and real-time control. 中文：洗衣机、汽车 ABS、微波炉常见。
Router:看到问硬件 device, 功能是 directs data packets，sending data, 无脑填 router
4. Software
Operating system:Manages memory, files, peripherals, user interface, security, multitasking and interrupts. 中文：OS 是硬件和用户/应用之间的管理层。
BIOS:BIOS is firmware stored in ROM/flash memory. It performs hardware checks when the computer starts, initializeshardware, finds the boot device, and starts loading the operating system.中文：刚开机时出现，在 OS 启动之前
Interrupts:Signal requiring CPU attention; CPU suspends current task, runs interrupt service routine, then returns. 中文：打印机缺纸、键盘输入都是例子。
Compiler:Translates whole program before execution; creates executable/object code; errors listed after compilation; executioncan be faster after translation. 中文：一次整体翻译。
Interpreter:Translates/executes line by line; easier debugging; no separate object code; slower repeated execution. 中文：逐行翻译。
Low-level vs high-level:Low-level closer to hardware and may be faster; high-level easier to read / write / maintain and portable.中文：assembly 用 assembler 翻译。
Integrated Development Environments (IDE):Code editors, Run-time environment, Translators, Errordiagnostics
5. The internet and its uses
The internet is a global network of interconnected computers and devices.It provides the physical and
technical infrastructure that allows data to be sent and received.
The World Wide Web (WWW)is a collection of websites and web pages that can be accessed via theinternet using web browsers.
URL:protocol( HTTPS, FTP, SMTP) + domain name + filename
IP vs MAC:IP address identifies a device on a network and can change(e.g.,192.168.1.1)
MAC is hardware address of network interface and usually fixed. 中文：IP 可变，MAC 固定。
DNS:Translates domain names into IP addresses so browsers can locate servers. 中文：域名到 IP 的“电话簿”。
HTTP/HTTPS:HTTP transfers web pages; HTTPS adds encryption/authentication using certificates, improving security. 中文：S = secure(SSL)。答题结合asymmetric
Web browsers:Storing bookmarks / favourites; Recording user history; Multiple tabs;Storing cookies; Navigation tools
Cybersecurity threats:Phishing tricks users into revealing data; malware damages/steals data; brute-force tries many passwords;DDoS overwhelms service. 中文：答案要写攻击方式 + 影响。proxy server 可以抵挡 DDoS
Protection:Strong passwords, 2FA, firewall, anti-malware, encryption, backups, user access levels, software updates. 中文：措施必须对应威胁。
6. Automated and emerging technologies
Monitoring vs control:Monitoring reads sensor data only; control uses sensor data to trigger actuator/output. 中文：control 必须有 actuator/action。
Feedback loop:Sensor input → processor compares with set point → actuator changes environment → repeat. 中文：温控,laser 系统常考。
AI / machine learning:AI systems can make decisions/predictions from data; benefits include automation and patternrecognition; risks include bias, privacy and accountability. 中文：评价题要正反两面。Ability to learn; Ability to adapt; Ability to reason; base on the knowledge base.
Cloud computing:Remote storage/processing via internet; benefits include access anywhere and scalability; risks includedependency on internet and data security. 中文：不要只写“more storage”，要联系远程访问。
IGCSE计算机 P1答题技巧
IGCSE计算机 P1易错点
把 “encryption” 写成 “prevents hacking”更准确。encryption makes intercepted data unreadable without the key.
比较题只写 A 的优点再写 B 的优点，没有逐点 paired comparison。
把 “error detection” 当成自动纠错；很多方法只是检测，需重传(ARQ)才恢复正确数据。
CPU 寄存器名称背了但功能混淆：PC = next instruction address; MAR = address being accessed; MDR =
data/instruction transferred.
文件大小忘记单位换算：bits → bytes divide by 8；KiB/MiB 与 KB/MB 题目若指定必须按题目。
安全题措施不对应威胁：phishing 主要靠 user awareness/2FA/URL checking；firewall 不等于万能。
评价题没有 judgement：最后必须写 “Overall, for this context…”
可直接套用的英文模板
- “This improves performance because …, so the user/system can …”
- “A is … whereas B is …”
- “The data is encrypted, so if it is intercepted it cannot be understood without the key.”
- “The sensor sends data to the processor; the processor compares it with a stored value; an actuator is triggered if needed.”
- “This is suitable in this context because … However, a limitation is … Overall …”
- “More detail/resolution increases the number of bits that must be stored, therefore increasing file size.”
IGCSE计算机真题
