Mecklenburg-Vorpommern Abitur Data Processing Technology - independent foundations cheat sheet
Mecklenburg-Vorpommern Abitur Data Processing Technology - independent foundations · Keep the key ideas within reach.
Programming and Software Development
Recursion needs a base case and progress toward that base case.
Overloading uses different signatures; overriding replaces an inherited method.
Unit tests isolate units; integration tests combine them.
Short-circuit evaluation can skip the right operand.
Pass-by-value copies arguments; pass-by-reference can mutate the caller's object.
Computational Thinking and Problem Solving
Decomposition breaks problems down; abstraction removes irrelevant detail.
Binary search requires sorted data and is O(log n).
Merge sort is O(n log n) worst case; bubble sort is O(n^2).
Trace tables prevent guessing about loop output.
Update search bounds to mid + 1 or mid - 1, not mid.
Computer architecture, logic and data representation
State whether addresses refer to bytes or words before calculating capacity.
Distinguish PC, instruction register, address register and data register.
For n-bit two’s complement the range is−2^(n−1) through 2^(n−1)−1.
Cache locality and pipeline hazards matter more than a clock-rate label alone.
Data representation, arrays, lists, trees and graphs
n-bit two's complement range is −2^(n−1) to 2^(n−1) − 1; negation is invert then add 1.
Normalised two's complement mantissa has differing top two bits: 01… for positive, 10… for negative.
Longer mantissa = more precision; longer exponent = more range.
Bitmap size = width × height × colour depth ÷ 8; sound size = rate × resolution × channels × seconds ÷ 8.
Stacks are LIFO, queues FIFO; hash tables give near-constant lookup; linked lists give O(1) insertion once positioned.
Lossless compression preserves all data (RLE, Huffman); lossy discards detail permanently (JPEG, MP3).
Computing Systems
Fetch-decode-execute uses the PC, IR, ALU, and registers.
Memory hierarchy: registers, cache, RAM, storage, offline.
RAM is volatile; SSDs retain data without power.
A process has its own address space; threads share one.
Authentication verifies identity; authorization grants permissions.
TCP is reliable and connection-oriented; UDP is connectionless and lower overhead.
IP addresses route between networks; MAC addresses work on the local link.
A /26 subnet has 64 addresses and 62 usable hosts.
DNS resolves names; DHCP assigns addresses.
Security protects data; privacy governs collection and use.
Operating systems, translation and concurrency
Draw a scheduling timeline before averaging waits.
Distinguish a TLB miss from a nonresident page fault.
LRU is a stack algorithm; FIFO can exhibit Belady’s anomaly.
Protect the shared invariant and analyze actual wait dependencies.
Identity, access and cryptographic protection
Identification, authentication, authorisation and accounting are four distinct steps.
MFA needs two different factor categories, not two instances of one.
RBAC suits stable job roles; ABAC suits context-dependent, fine-grained rules.
Kerberos uses a KDC with TGT and service tickets for SSO.
Symmetric ciphers handle bulk data; asymmetric ciphers solve key distribution and signatures.
Signing uses a specified signature scheme with the signer’s private key; verification and custody are essential to origin evidence.
ECB leaks patterns; use authenticated modes such as GCM or encrypt-then-MAC.
Assembly tracing and bounded physical-computing models
State the instruction set, operand order, width and branch condition before tracing.
Follow register, memory and program-counter changes after each instruction.
Unsigned modular arithmetic is different from a claim about signed overflow.
Separate sensing, processing, communication and actuation.