Summary

This is an NES emulator library written in D. It started as a port to D from Go of github.com/fogleman/nes. It's pure D & has no dependencies.

Installation

Just add "nes": "~>0.2.0" or "nes" version="~>0.2.0" to the dependencies section of your dub.json or dub.sdl file.

Usage

See github.com/blahness/nes_test for an example usage.

Mappers

The following mappers have been implemented:

• NROM (0)
• MMC1 (1)
• UNROM (2)
• CNROM (3)
• MMC3 (4)
• AOROM (7)
• 255

Test ROM Results

CPU Tests

Name	Results
branch_timing_tests	3/3 Pass 1.Branch_Basics ✔️ 2.Backward_Branch ✔️ 3.Forward_Branch ✔️
cpu_interrupts_v2	6/6 Pass cpu_interrupts ✔️ 1-cli_latency ✔️ 2-nmi_and_brk ✔️ 3-nmi_and_irq ✔️ 4-irq_and_dma ✔️ 5-branch_delays_irq ✔️
cpu_timing_test6	Pass
instr_test-v5	18/18 Pass all_instrs ✔️ official_only ✔️ 01-basics ✔️ 02-implied ✔️ 03-immediate ✔️ 04-zero_page ✔️ 05-zp_xy ✔️ 06-absolute ✔️ 07-abs_xy ✔️ 08-ind_x ✔️ 09-ind_y ✔️ 10-branches ✔️ 11-stack ✔️ 12-jmp_jsr ✔️ 13-rts ✔️ 14-rti ✔️ 15-brk ✔️ 16-special ✔️
instr_timing	3/3 Pass instr_timing ✔️ 1-instr_timing ✔️ 2-branch_timing ✔️
nestest	Pass

PPU Tests

Name	Results
blargg_ppu_tests_2005.09.15b	5/5 Pass palette_ram ✔️ power_up_palette ✔️ sprite_ram ✔️ vbl_clear_time ✔️ vram_access ✔️
nmi_sync	0/2 Pass demo_ntsc ❌ demo_pal ❌
ppu_sprite_hit	11/11 Pass ppu_sprite_hit ✔️ 01-basics ✔️ 02-alignment ✔️ 03-corners ✔️ 04-flip ✔️ 05-left_clip ✔️ 06-right_edge ✔️ 07-screen_bottom ✔️ 08-double_height ✔️ 09-timing ✔️ 10-timing_order ✔️
ppu_vbl_nmi	11/11 Pass ppu_vbl_nmi ✔️ 01-vbl_basics ✔️ 02-vbl_set_time ✔️ 03-vbl_clear_time ✔️ 04-nmi_control ✔️ 05-nmi_timing ✔️ 06-suppression ✔️ 07-nmi_on_timing ✔️ 08-nmi_off_timing ✔️ 09-even_odd_frames ✔️ 10-even_odd_timing ✔️
scanline	Pass

APU Tests

Name	Results	Notes
apu_mixer	4/4 Pass dmc ✔️ noise ✔️ square ✔️ triangle ✔️
apu_phase_reset	Pass
apu_reset	6/6 Pass 4015_cleared ✔️ 4017_timing ✔️ 4017_written ✔️ irq_flag_cleared ✔️ len_ctrs_enabled ✔️ works_immediately ✔️
apu_test	9/9 Pass apu_test ✔️ 1-len_ctr ✔️ 2-len_table ✔️ 3-irq_flag ✔️ 4-jitter ✔️ 5-len_timing ✔️ 6-irq_flag_timing ✔️ 7-dmc_basics ✔️ 8-dmc_rates ✔️
blargg_apu_2005.07.30	11/11 Pass 01.len_ctr ✔️ 02.len_table ✔️ 03.irq_flag ✔️ 04.clock_jitter ✔️ 05.len_timing_mode0 ✔️ 06.len_timing_mode1 ✔️ 07.irq_flag_timing ✔️ 08.irq_timing ✔️ 09.reset_timing ✔️ 10.len_halt_timing ✔️ 11.len_reload_timing ✔️
dmc_tests	4/4 Pass buffer_retained ✔️ latency ✔️ status ✔️ status_irq ✔️
dpcmletterbox	Pass	HSYNC timing issues create flicker when scrolling
fadeout_and_triangle_test	Pass
square_timer_div2	Pass
test_apu_2	10/10 Pass test_1 ✔️ test_2 ✔️ test_3 ✔️ test_4 ✔️ test_5 ✔️ test_6 ✔️ test_7 ✔️ test_8 ✔️ test_9 ✔️ test_10 ✔️
test_apu_env	Pass
test_apu_m	3/3 Pass test_9 ✔️ test_10 ✔️ test_11 ✔️
test_apu_sweep	2/2 Pass sweep_cutoff ✔️ sweep_sub ✔️
test_apu_timers	4/4 Pass dmc_pitch ✔️ noise_pitch ✔️ square_pitch ✔️ triangle_pitch ✔️
test_tri_lin_ctr	Pass
volume_tests	Pass

Known Issues

• there are some minor issues with PPU timing, but most games work OK anyway
• the APU emulation isn't quite perfect, but not far off
• only NTSC timing supported for now