64bitPCille

64bitPCille is a fictional 64-bit personal computing platform introduced for educational and speculative discussion of modern computer architecture. It describes a complete stack including an instruction set architecture (ISA), a reference implementation, and a software ecosystem used in textbooks and classroom exercises to illustrate architectural trade-offs in 64-bit systems.

The architecture of 64bitPCille centers on a 64-bit address space and 64-bit general-purpose registers. It employs a simplified, primarily load/store RISC-like ISA with a modest fixed instruction encoding and optional extensions for multimedia and security features. The default memory model uses virtual memory with standard page-based protection and a 64-bit virtual address space, while a physical memory model supports large pages for performance. The platform emphasizes a clean separation of compiler back-end and runtime, and supports pipeline and cache concepts to enable discussions of instruction-level parallelism, branch prediction, and memory hierarchies without tying to a specific real-world CPU.

Software on 64bitPCille includes a reference operating system called 64PCOS and a minimal standard library. The project is used in education to demonstrate how 64-bit addressing, calling conventions, and system calls interact, as well as to compare different memory-management strategies and compiler options.

64bitPCille has had limited practical adoption and remains primarily a teaching tool. It appears in curricula, textbooks, and speculative design exercises as a neutral baseline for discussing the principles of 64-bit computing.

See also: 64-bit computing, x86-64, ARM64, memory management, instruction set architecture.