diff --git a/lib/rouge/demos/nesasm b/lib/rouge/demos/nesasm
new file mode 100644
index 0000000000..91a0f972f3
--- /dev/null
+++ b/lib/rouge/demos/nesasm
@@ -0,0 +1,11 @@
+  .bank 0
+  .org $C000
+Reset:	
+        jsr WaitSync	; wait for VSYNC
+        jsr ClearRAM	; clear RAM
+        jsr WaitSync	; wait for VSYNC (and PPU warmup)
+
+	lda #$3f	; $3F -> A register
+        ldy #$00	; $00 -> Y register
+        sta PPU_ADDR	; write #HIGH byte first
+        sty PPU_ADDR    ; $3F00 -> PPU address
\ No newline at end of file
diff --git a/lib/rouge/lexers/nesasm.rb b/lib/rouge/lexers/nesasm.rb
new file mode 100644
index 0000000000..a296414e04
--- /dev/null
+++ b/lib/rouge/lexers/nesasm.rb
@@ -0,0 +1,78 @@
+# -*- coding: utf-8 -*- #
+# frozen_string_literal: true
+
+module Rouge
+  module Lexers
+    class NesAsm < RegexLexer
+      title "NesAsm"
+      desc "Nesasm3 assembly (6502 asm)"
+      tag 'nesasm'
+      aliases 'nes'
+      filenames '*.nesasm'
+
+      def self.keywords
+        @keywords ||= %w(
+          ADC AND ASL BIT BRK CMP CPX CPY DEC EOR INC JMP JSR LDA LDX LDY LSR
+          NOP ORA ROL ROR RTI RTS SBC STA STX STY TAX TXA DEX INX TAY TYA DEY
+          INY BPL BMI BVC BVS BCC BCS BNE BEQ CLC SEC CLI SEI CLV CLD SED TXS
+          TSX PHA PLA PHP PLP
+        )
+      end
+
+      def self.keywords_type
+        @keywords_type ||= %w(
+          DB DW BYTE WORD 
+        )
+      end
+
+      def self.keywords_reserved
+        @keywords_reserved ||= %w(
+          INCBIN INCLUDE ORG BANK RSSET RS MACRO ENDM DS PROC ENDP PROCGROUP
+          ENDPROCGROUP INCCHR DEFCHR ZP BSS CODE DATA IF IFDEF IFNDEF ELSE
+          ENDIF FAIL INESPRG INESCHR INESMAP INESMIR FUNC
+        )
+      end
+      
+      state :root do
+        rule %r/\s+/m, Text
+        rule %r(;.*), Comment::Single
+
+        rule %r/[\(\)\,\.\[\]]/, Punctuation 
+        rule %r/\#?\%[0-1]+/, Num::Bin # #%00110011 %00110011
+        rule %r/\#?\$\h+/, Num::Hex  # $1f #$1f
+        rule %r/\#?\d+/, Num # 10 #10
+        rule %r([~&*+=\|?:<>/-]), Operator
+
+        rule %r/\#?\w+:?/i do |m|
+          name = m[0].upcase
+          
+          if self.class.keywords.include? name
+            token Keyword
+          elsif self.class.keywords_type.include? name
+            token Keyword::Type
+          elsif self.class.keywords_reserved.include? name
+            token Keyword::Reserved
+          else
+            token Name::Function
+          end
+        end
+
+        rule %r/\#?(?:LOW|HIGH)\(.*\)/i, Keyword::Reserved # LOW() #HIGH()
+        
+        rule %r/\#\(/, Punctuation # #()
+
+        rule %r/"/, Str, :string
+
+        rule %r/'\w'/, Str::Char # 'A' for example
+        
+        rule %r/\\\??[\d@#]/, Name::Builtin # builtin parameters for use inside macros and functions:   \1-\9 , \?1-\?9 , \# , \@
+      end
+
+      state :string do
+        rule %r/"/, Str, :pop!
+        rule %r/\\"?/, Str::Escape
+        rule %r/[^"\\]+/m, Str
+      end
+    end
+  end
+end
diff --git a/spec/lexers/nesasm_spec.rb b/spec/lexers/nesasm_spec.rb
new file mode 100644
index 0000000000..7b37f931e6
--- /dev/null
+++ b/spec/lexers/nesasm_spec.rb
@@ -0,0 +1,14 @@
+# -*- coding: utf-8 -*- #
+# frozen_string_literal: true
+
+describe Rouge::Lexers::NesAsm do
+  let(:subject) { Rouge::Lexers::NesAsm.new }
+
+  describe 'guessing' do
+    include Support::Guessing
+
+    it 'guesses by filename' do
+      assert_guess :filename => 'foo.nesasm'
+    end
+  end
+end
diff --git a/spec/visual/samples/nesasm b/spec/visual/samples/nesasm
new file mode 100644
index 0000000000..6615b3c6a2
--- /dev/null
+++ b/spec/visual/samples/nesasm
@@ -0,0 +1,69 @@
+  .inesprg 2   ; 2x 16KB PRG code banks
+  .ineschr 1   ; 1x  8KB CHR data banks 
+  .inesmap 0   ; mapper (0 = NROM), no bank swapping
+  .inesmir 0   ; 0 = horizontal background mirroring (for vertical scrolling)
+
+  ;;;;;; VARIABLES
+  .rsset $0000 ; zero page
+
+gamestate  .rs 1
+playerx    .rs 2
+
+  .bank 1
+  .org $C000 
+
+Reset:
+  jsr WaitSync	; wait for VSYNC
+  jsr ClearRAM	; clear RAM
+  jsr WaitSync	; wait for VSYNC (and PPU warmup)
+
+SCR_ADDR .func (\1) + ((\2) << 5)
+
+abs    .macro
+  lda   \1
+  bpl   .x\@
+  eor   #$FF
+  inc   A
+  sta   \1
+
+  lda \#
+  sta numberOfParams
+
+  lda \?4
+  sta typeOfParam
+
+  .x\@:
+    .endm
+
+NMI:
+  LoadSprites:
+  ldx #$00
+LoadSpritesLoop:
+  lda Sprites, x
+  sta OAM_RAM, x
+  inx 
+  cpx #$10
+  bne LoadSpritesLoop
+
+  lda #HIGH(background)
+  sta backHi
+  lda #LOW(background)
+  sta backLo
+
+Sprites:
+  ;vert tile attr horiz
+  .db $80, $01, %00000000, $80   ;sprite 0
+  .db $80, $02, %00110011, $88   ;sprite 1
+  .db $88, $03, %00110011, $80   ;sprite 2
+  .db $88, $05, %00000000, $88   ;sprite 3
+
+  .include "somefile.asm"
+  .incbin "somefile.chr"
+  background:
+    .incbin "background.chr"
+
+;; CPU interrupts
+  .org $FFFA     
+  .dw NMI        ; vblank NMI
+  .dw RESET      ; Reset
+  .dw 0          ; IRQ
\ No newline at end of file