Description

The ao486 is an x86 compatible Verilog core implementing all features of a 486 SX. The core was modeled and tested based on the Bochs software x86 implementation. Together with the 486 core, the ao486 project also contains a SoC capable of booting the Linux kernel version 3.13 and Microsoft Windows 95.

Current status

31 March 2014 - initial version 1.0.

19 August 2014 - driver_sd update, ps2 fix.

Features

The ao486 processor model has the following features:

pipeline architecture with 4 main stages: decode, read, execute and write,

all 486 instructions are implemented, together with CPUID,

16 kB instruction cache,

16 kB write-back data cache,

TLB for 32 entries,

Altera Avalon interfaces for memory and io access.

The ao486 SoC consists of the following components:

ao486 processor,

IDE hard drive that redirects to a HDL SD card driver,

floppy controller that also redirects to the SD card driver,

8259 PIC,

8237 DMA,

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