LISP machine platforms: Which hardware features were typically associated with classic LISP machines used for AI research?

Introduction / Context:
LISP machines (from vendors such as Symbolics and Lisp Machines, Inc.) were engineered to accelerate symbolic processing for AI. This question examines your knowledge of their characteristic hardware traits.

Given Data / Assumptions:

• Goal: accelerate garbage collection, dynamic typing, and list processing.
• UI catered to development: rich keyboards and pointing devices.
• Period: 1980s specialized workstations.

Concept / Approach:
These systems paired generous memory and specialized CPUs or microcode with development-friendly peripherals, including mice and keyboards with dedicated Lisp editing keys and symbols, to support interactive environments.

Step-by-Step Solution:

Verification / Alternative check:
Historical documentation highlights hardware support for tagged architectures, stack-based execution, and integrated GUIs with tailored input devices.

Why Other Options Are Wrong:

• Letter-quality printers and 8-inch drives were era-typical peripherals, not defining features of Lisp machines.
• ‘‘None of the above’’ ignores well-documented specifications.

Common Pitfalls:
Attributing generic office peripherals as core identifiers; what set these machines apart was architecture and developer I/O design.

Final Answer:
Both (a) and (c)