Category Archive: 6502

May 10

NES FPGA: First Run

I’ve managed to get the nestest rom to run on my emulator.  I’m still nowhere near complete but this is a good first step.  Video is working, at least without sprites.  Control input works, although there’s a bug floating around in there somewhere   I’m currently working on getting the APU ( Audio Processing Unit) up and …

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Apr 17

NES FPGA : Mini Breakthroughs


I’ve made significant progress since my first stumbling block.  I’ve rewritten my 6502 core so that it is synthesizable and have successfully deployed it to my nanoboard.  I have been able to tweak the data bus such that I can communicate with the internal cartridge, my PPU, and the external SRAM available on the nanoboard.  This has …

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Apr 05

Of Simulation and Synthesis

Log Comparison

I’ve made significant progress on my 6502 FPGA Emulation, and even have a mostly complete layout of the NES Picture Processing Unit.  I set up a test-bench that included RAM and cartridge simulation and logged the processor output to a text file that could be compared to the “golden” nestest log.  I was able to debug all …

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Mar 22

FPGA 6502 Emulator: First Life


There’s an amazing project known as Visual 6502.  They have created a transistor level net-list of the 6502 processor which can in turn be converted into synthesizable VHDL.  As nice as this is, I’ve decided that would be far too easy and am going to go ahead and emulate the 6502 core before I fool around with a proper simulation.  I’ve …

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