Primary source: Released examination archive, member 4224-1.pdf. The original nine-page scan identifies the University of Oxford Preliminary Examination in computer science on 14 June 2013. Questions 1–3 cover digital electronics, the datapath and file systems; Questions 4–6 cover linear algebra; Questions 7–8 use the supplied natural deduction rules on printed p. 9. The original p. 8 repeats Question 8(a)(i) as Question 8(a)(iii), and has a redundant closing parenthesis in Question 7(d)(i).

Original University of Oxford Preliminary Examination in Computer Science, 22 September 2005. Released in the examination archive, member 4214.pdf, six printed pages.

Original six-page Preliminary Examination, Long Vacation 2005, released as member 4213.pdf of the examination archive. Printed p. 2 has identical right folds on the two sides of Question 1(c). Printed p. 5 says “even” for a list of odd prime numbers in Question 9(b). Both readings are visible in the original scan.

Original seven-page Preliminary Examination in computer science, Long Vacation, 25 September 2003. Released in the examination archive, member 4214-1.pdf. The printed cover identifies Paper 2. Question 7's definition of a directed set does not exclude the empty set; under that convention its completeness assumption also requires a least element.

The eight-page Preliminary Examination in Computer Science, Paper 1, Long Vacation 2003. Original source: Released examination archive, member 4213-1.pdf. Printed pp. 2–3 cover functional programming, p. 4 covers algorithms, pp. 5–6 cover imperative programming, and pp. 7–8 cover digital electronics. The timing diagram on printed p. 8 permits a new clock cycle pulse immediately after a cycle that rearms the circuit.

The bit rate counts transmitted data bits per unit time. State which representation is being counted: payload bits and encoded link bits need not have the same rate.

The symbol rate, measured in baud, counts signal elements per second. Its relation to bit rate depends on the representation and on which signal element is counted as a symbol.

A line code maps data to a sequence of physical signal levels or transitions for transmission. Timing, polarity and the length of runs of equal levels affect the choice.

Multicast delivers data to a group of interested receivers. A multicast distribution tree can share transmissions over common links and copy them where routes branch.

Unicast addresses a transmission to a single destination, in contrast with group-addressed multicast delivery.

A computer network with nodes connected around a cycle. A unidirectional ring network permits messages to move only in the chosen direction.

A memory read through an address whose contents are fixed during ordinary operation. Used as a Boolean function lookup table, $a$ address bits select one of $2^a$ words, each holding $b$ output bits, so the logical table capacity is $2^{a}b$ bits. A finite-state machine can store its next-state function in such a table while separate flip-flops store the current state.

A memory access whose execution is observable under the source language or machine rules, so that replacing repeated accesses by a saved value can change behavior. The precise guarantees depend on the programming language; volatile access alone does not provide thread synchronization.

Storage for pending writes, usually with their memory addresses, data and status. A younger load instruction must account for older overlapping buffered store instructions, often by store-to-load forwarding.

An individually addressable place in computer memory holding a value. An abstract memory interface can separate reading and updating existing memory locations from allocating a fresh memory location.

Computer memory that retains stored information without power.

Projection from a fixed centre onto an image plane. With centre at the origin and plane $z=f$, a point $(x,y,z)$ with $z\ne 0$ maps to $(fx/z,fy/z,f)$. The image-plane convention may put the plane in front of the centre, giving a virtual upright image, or behind it, giving an inverted physical image.

Discarding surfaces viewed from their back side under a chosen vertex-winding and outward-normal vector convention. For an outward normal vector $n$ and an approaching ray direction $r$, a front-facing hit has $n\cdot r<0$.

Bui Tuong Phong's empirical local lighting model combines ambient illumination, cosine-weighted Lambertian reflectance, and a specular highlight about the specular reflection direction. The exponent of the specular lobe controls highlight width. It is distinct from interpolating normal vectors across a triangle.

Rendering by tracing geometric rays to surfaces, selecting visible intersections and evaluating illumination. Primary rays determine camera visibility, while shadow rays test visibility of light sources; recursive variants trace reflected and transmitted continuations.