From 27b9d4c1206d2d6c10186359340570ba8fd5befb Mon Sep 17 00:00:00 2001 From: vin Date: Wed, 21 Aug 2024 17:46:30 -0400 Subject: [PATCH] added snippet explaining the NES's 6502 variant and long-term goal for the project --- README.md | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/README.md b/README.md index 1d535ef..aebb58e 100644 --- a/README.md +++ b/README.md @@ -2,10 +2,20 @@ A Nintendo Entertainment System (NES) emulator written for the purpose of understanding how the NES and similar 8-bit computers of that era worked. -Makes heavy use of https://www.nesdev.org/. +The NES used a variant of the MOS 6502 8-bit microcontroller called a +Ricoh 2A03 that contained the 6502 without the BCD mode for arithmetic, +an audio signal generator (APU), controlling the gamepads, and for DMA. +([Source: NESdev](https://www.nesdev.org/wiki/DMA)) + +A major goal for the emulator is finishing the software implementation +in C and later implement this in hardware with either an FPGA or another +CPU like a RISC-V. Later, I want to generalize the 2A03 simulator into +a full 6502 for use with a Commodore 64 and Apple II. + +Makes heavy use of the [NESdev wiki](https://www.nesdev.org/wiki). ## Current State -- [x] CPU (2A03/6502) +- [x] CPU (Ricoh 2A03, variant of MOS 6502) - [ ] PPU (Graphics) - [ ] APU (Audio)