microcode

Tag

Cards List
#microcode

80386 Early Start Memory Access

Hacker News Top · 2026-06-23 Cached

The article explains the Early Start memory access technique in Intel's 80386, which hides memory latency by overlapping address generation with the previous instruction's last cycle. It describes the implementation of this technique in the z386 FPGA core, achieving ao486-class performance and a 39% improvement in Doom FPS.

0 favorites 0 likes
#microcode

Microcode inside the Intel 8087 floating-point chip: register exchange

Hacker News Top · 2026-05-30 Cached

A detailed reverse-engineering analysis of the microcode inside the Intel 8087 floating-point coprocessor, focusing on the FXCH register exchange instruction and the chip's internal architecture.

0 favorites 0 likes
#microcode

z386: An Open-Source 80386 Built Around Original Microcode

Hacker News Top · 2026-05-23 Cached

The article details z386, an open-source FPGA implementation of an 80386 CPU built using the original Intel microcode. It can boot DOS 6/7, run protected-mode programs, and play classic games like Doom, serving as both an educational reconstruction and a usable FPGA CPU.

0 favorites 0 likes
#microcode

80386 Microcode Disassembled

Hacker News Top · 2026-05-23 Cached

A blog post detailing the successful disassembly and analysis of the Intel 80386 microcode, revealing 215 instruction entry points and the complex internal architecture.

0 favorites 0 likes
#microcode

Designing a Scientific Calculator from scratch in FPGA

Lobsters Hottest · 2026-05-17 Cached

A detailed blog series documenting the design and implementation of a scientific calculator from scratch using FPGA, covering numerical methods, CPU architecture, microcode, and hardware prototyping.

0 favorites 0 likes
#microcode

I designed a nibble-oriented CPU in Verilog to build a scientific calculator

Hacker News Top · 2026-05-15 Cached

This project implements a fully functional scientific calculator in hardware using an FPGA, including a custom soft CPU, microcode firmware, and supporting tools. It provides a web-based simulator and open-source Verilog code.

0 favorites 0 likes
#microcode

Instruction decoding in the Intel 8087 floating-point chip

Ken Shirriff · 2026-02-14 Cached

A detailed reverse-engineering analysis of how the Intel 8087 floating-point coprocessor decodes instructions, explaining the interplay between the main CPU and coprocessor, the use of microcode ROM, and the bus interface unit.

0 favorites 0 likes
#microcode

Notes on the Intel 8086 processor's arithmetic-logic unit

Ken Shirriff · 2026-01-23 Cached

A detailed technical analysis of the Intel 8086 processor's arithmetic-logic unit (ALU) control circuitry, explaining how microcode and control signals coordinate to perform 28 different operations.

0 favorites 0 likes
#microcode

Conditions in the Intel 8087 floating-point chip's microcode

Ken Shirriff · 2025-12-30 Cached

A detailed examination of the conditional tests used in the Intel 8087 floating-point coprocessor's microcode, part of a reverse-engineering effort to understand its algorithms.

0 favorites 0 likes
#microcode

Notes on the Pentium's microcode circuitry

Ken Shirriff · 2025-03-31 Cached

A detailed examination of the Pentium processor's microcode ROM, describing its structure, capacity, and how microcode implements machine instructions at the hardware level.

0 favorites 0 likes
← Back to home

Submit Feedback