diff --git a/go/asm/asm.go b/go/asm/asm.go
new file mode 100644
index 0000000..1069411
--- /dev/null
+++ b/go/asm/asm.go
@@ -0,0 +1,118 @@
+package asm
+
+import (
+	"fmt"
+	"io"
+	"strings"
+
+	"github.com/alecthomas/participle/v2"
+	"github.com/alecthomas/participle/v2/lexer"
+)
+
+type Asm struct {
+	Instructions []*Instruction `@@*`
+}
+
+type Display struct {
+	Sym string `@Sym Whitespace`
+	Val string `@Quote @Sym @Quote Whitespace`
+}
+
+func(d Display) String() string {
+	return fmt.Sprintf("Display: %v %v", d.Sym, d.Val)
+}
+
+type Sig struct {
+	Sym string `@Sym Whitespace`
+	Size uint32 `@Size Whitespace`
+	Val uint32 `@Size Whitespace`
+}
+
+func(s Sig) String() string {
+	return fmt.Sprintf("Sig: %v %v %v", s.Sym, s.Size, s.Val)
+}
+
+type Single struct {
+	One string `@Sym Whitespace`
+}
+
+func(s Single) String() string {
+	return fmt.Sprintf("Single: %v", s.One)
+}
+
+type Double struct {
+	One string `@Sym Whitespace`
+	Two string `@Sym Whitespace`
+}
+
+func(d Double) String() string {
+	return fmt.Sprintf("Double: %v %v", d.One, d.Two)
+}
+
+type Sized struct {
+	Sym string `@Sym Whitespace`
+	Size uint32 `@Size Whitespace`
+	X uint32 `(@Size Whitespace)?`
+}
+
+func(s Sized) String() string {
+	return fmt.Sprintf("Sized: %v %v", s.Sym, s.Size)
+}
+
+type Arg struct {
+	ArgNone string "Whitespace?"
+	ArgDisplay *Display `@@?`
+	ArgSized *Sized `@@?`
+	ArgSingle *Single `@@?`
+	ArgDouble *Double `@@?`
+}
+
+func (a Arg) String() string {
+	if a.ArgDisplay != nil {
+		return fmt.Sprintf("%s", a.ArgDisplay)
+	}
+	if a.ArgSized != nil {
+		return fmt.Sprintf("%s", a.ArgSized)
+	}
+	if a.ArgSingle != nil {
+		return fmt.Sprintf("%s", a.ArgSingle)
+	}
+	if a.ArgDouble != nil {
+		return fmt.Sprintf("%s", a.ArgDouble)
+	}
+	return ""
+}
+
+type Instruction struct {
+	OpCode string `@Ident`
+	OpArg Arg `@@`
+	Comment string `Comment?`
+}
+
+func (i Instruction) String() string {
+	return fmt.Sprintf("%s %s", i.OpCode, i.OpArg)
+}
+
+var (
+	asmLexer = lexer.MustSimple([]lexer.SimpleRule{
+		{"Comment", `(?:#)[^\n]*\n?`},
+		{"Ident", `^[A-Z]+`},
+		{"Sym", `[a-zA-Z]+`},
+		{"Size", `[0-9]+`},
+		{"Whitespace", `[ \t\n\r]+`},
+		{"Quote", `["']`},
+	})
+	asmParser = participle.MustBuild[Asm](
+		participle.Lexer(asmLexer),
+		participle.Elide("Comment", "Whitespace"),
+	)
+)
+
+func Parse(s string, w io.Writer) (int, error) {
+	rd := strings.NewReader(s)
+	ast, err := asmParser.Parse("file", rd)
+	for i, v := range ast.Instructions {
+		fmt.Printf("%v %v\n", i, v)
+	}
+	return 0, err
+}
diff --git a/go/asm/asm_test.go b/go/asm/asm_test.go
new file mode 100644
index 0000000..83ed58f
--- /dev/null
+++ b/go/asm/asm_test.go
@@ -0,0 +1,26 @@
+package asm
+
+import (
+	"log"
+	"testing"
+
+	"git.defalsify.org/festive/vm"
+)
+
+
+func TestParserInit(t *testing.T) {
+	var b []byte
+	b = vm.NewLine(b, vm.HALT, nil, nil, nil)
+	b = vm.NewLine(b, vm.CATCH, []string{"xyzzy"}, []byte{0x02, 0x9a}, []uint8{1})
+	b = vm.NewLine(b, vm.LOAD, []string{"foo"}, []byte{42}, nil)
+	b = vm.NewLine(b, vm.MOUT, []string{"bar", "barbarbaz"}, nil, nil)
+	s, err := vm.ToString(b)
+	log.Printf("parsing:\n%s\n", s)
+	n, err := Parse(s, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if n != 0 {
+		t.Fatalf("expected 0 byte write count, got %v", n)
+	}
+}
diff --git a/go/vm/interpreter.go b/go/asm/menu.go
similarity index 77%
rename from go/vm/interpreter.go
rename to go/asm/menu.go
index 90fbb43..1f415ef 100644
--- a/go/vm/interpreter.go
+++ b/go/asm/menu.go
@@ -1,7 +1,9 @@
-package vm
+package asm
 
 import (
 	"fmt"
+
+	"git.defalsify.org/festive/vm"
 )
 
 type BatchCode uint16
@@ -61,19 +63,21 @@ func (mp *MenuProcessor) ToLines() []byte {
 	postLines := []byte{}
 
 	for _, v := range mp.items {
-		preLines = NewLine(preLines, MOUT, []string{v.choice, v.display}, nil, nil)
+		preLines = vm.NewLine(preLines, vm.MOUT, []string{v.choice, v.display}, nil, nil)
 		switch v.code {
 		case MENU_UP:
-			postLines = NewLine(postLines, INCMP, []string{v.choice, "_"}, nil, nil)
+			postLines = vm.NewLine(postLines, vm.INCMP, []string{v.choice, "_"}, nil, nil)
 		case MENU_NEXT:
 			_ = postLines
 		case MENU_PREVIOUS:
 			_ = postLines
 		default:
-			postLines = NewLine(postLines, INCMP, []string{v.choice, v.target}, nil, nil)
+			postLines = vm.NewLine(postLines, vm.INCMP, []string{v.choice, v.target}, nil, nil)
 		}
 	}
 
-	preLines = NewLine(preLines, HALT, nil, nil, nil)
+	preLines = vm.NewLine(preLines, vm.HALT, nil, nil, nil)
 	return append(preLines, postLines...)
 }
+
+
diff --git a/go/vm/interpreter_test.go b/go/asm/menu_test.go
similarity index 91%
rename from go/vm/interpreter_test.go
rename to go/asm/menu_test.go
index 33af62c..426339d 100644
--- a/go/vm/interpreter_test.go
+++ b/go/asm/menu_test.go
@@ -1,7 +1,9 @@
-package vm
+package asm
 
 import (
 	"testing"
+
+	"git.defalsify.org/festive/vm"
 )
 
 
@@ -28,7 +30,7 @@ func TestMenuInterpreter(t *testing.T) {
 		t.Errorf("expected error on invalid menu item 'BOGUS'")
 	}
 	b := m.ToLines()
-	r, err := ToString(b)
+	r, err := vm.ToString(b)
 	if err != nil {
 		t.Fatal(err)
 	}
diff --git a/go/go.mod b/go/go.mod
index 77af5ba..e70f0c4 100644
--- a/go/go.mod
+++ b/go/go.mod
@@ -2,4 +2,7 @@ module git.defalsify.org/festive
 
 go 1.20
 
-require github.com/peteole/testdata-loader v0.3.0
+require (
+	github.com/alecthomas/participle/v2 v2.0.0
+	github.com/peteole/testdata-loader v0.3.0
+)
diff --git a/go/vm/debug.go b/go/vm/debug.go
index 7c25369..6b912a8 100644
--- a/go/vm/debug.go
+++ b/go/vm/debug.go
@@ -52,7 +52,8 @@ func ParseAll(b []byte, w io.Writer) (int, error) {
 						vv = 1
 					}
 					if w != nil {
-						rs = fmt.Sprintf("%s %s %v %v # invertmatch=%v\n", s, r, n, vv, m)
+						//rs = fmt.Sprintf("%s %s %v %v # invertmatch=%v\n", s, r, n, vv, m)
+						rs = fmt.Sprintf("%s %s %v %v\n", s, r, n, vv)
 					}
 				}
 			}
@@ -65,7 +66,8 @@ func ParseAll(b []byte, w io.Writer) (int, error) {
 					if m {
 						vv = 1
 					}
-					rs = fmt.Sprintf("%s %v %v # invertmatch=%v\n", s, n, vv, m)
+					//rs = fmt.Sprintf("%s %v %v # invertmatch=%v\n", s, n, vv, m)
+					rs = fmt.Sprintf("%s %v %v\n", s, n, vv)
 				}
 			}
 		case LOAD:
@@ -153,7 +155,7 @@ func ParseAll(b []byte, w io.Writer) (int, error) {
 				return rn, err
 			}
 			rn += n
-			log.Printf("wrote %v bytes from instruction %v", n, s)
+			log.Printf("wrote %v bytes for instruction %v", n, s)
 		}
 
 		//rs += "\n"