diff --git a/build.sbt b/build.sbt
index 44f61ea..2cb6c21 100644
--- a/build.sbt
+++ b/build.sbt
@@ -17,7 +17,7 @@ lazy val demo =
   module("demo")
     .dependsOn(core)
     .withEfectMonad
-    .settings(libraryDependencies += "com.htmlism" %% "rufio-zio" % "74-5cd25e9b")
+    .settings(libraryDependencies += "com.htmlism" %% "rufio-zio" % "76-c565ab28")
 
 ThisBuild / resolvers += "mcanlas/rufio" at "https://maven.pkg.github.com/mcanlas/rufio/"
 
diff --git a/data/one-line.txt b/data/one-line.txt
deleted file mode 100644
index e3c0674..0000000
--- a/data/one-line.txt
+++ /dev/null
@@ -1 +0,0 @@
-one line
diff --git a/firepower-demo/src/main/scala/com/htmlism/firepower/demo/FeatureDemo.scala b/firepower-demo/src/main/scala/com/htmlism/firepower/demo/FeatureDemo.scala
index 57d31b1..7f7d06e 100644
--- a/firepower-demo/src/main/scala/com/htmlism/firepower/demo/FeatureDemo.scala
+++ b/firepower-demo/src/main/scala/com/htmlism/firepower/demo/FeatureDemo.scala
@@ -8,7 +8,7 @@ import com.htmlism.firepower.core.AsmBlock._
 import com.htmlism.firepower.core._
 
 object FeatureDemo:
-  val program: String =
+  val program: List[String] =
     List(
       CommentBlock.fromMultiline(asciiArt),
       CommentBlock(List("Change direction: W A S D")),
@@ -53,7 +53,6 @@ object FeatureDemo:
     )
       .map(AsmBlock.toLines(AssemblerOptions.InstructionCase.Lowercase))
       .pipe(xs => AsmBlock.interFlatMap(xs)(List("", ""), identity))
-      .pipe(str.Line.mkString)
 
   private lazy val asciiArt =
     """ ___           _        __ ___  __ ___
diff --git a/firepower-demo/src/main/scala/com/htmlism/firepower/demo/PrintPrograms.scala b/firepower-demo/src/main/scala/com/htmlism/firepower/demo/PrintPrograms.scala
index 8948585..a6a57e5 100644
--- a/firepower-demo/src/main/scala/com/htmlism/firepower/demo/PrintPrograms.scala
+++ b/firepower-demo/src/main/scala/com/htmlism/firepower/demo/PrintPrograms.scala
@@ -10,30 +10,20 @@ import zio.*
 import com.htmlism.firepower.core.AsmBlock._
 import com.htmlism.firepower.core.AssemblerOptions._
 import com.htmlism.firepower.core._
-import com.htmlism.firepower.demo.str._
 import com.htmlism.rufio.withzio.*
 
 object PrintPrograms extends ZIOAppDefault:
-  private def writeLine(file: String)(s: String) =
-    File(s"data/$file.txt")
-      .writeLine(s)
-
   private val programs =
-    List[(String, String)](
-      // FEATURE: writing a string to a file is easy (thanks, rufio)
-      "one-line.txt" -> "one line",
-
-      // FEATURE: writing lines to a file is easy
-      "two-lines.txt" -> List("foo", "bar")
-        .pipe(Line.mkString),
+    List[(String, List[String])](
+      // FEATURE: writing lines to a file is easy (thanks, rufio)
+      "two-lines.txt" -> List("foo", "bar"),
 
       // FEATURE: writing paragraphs separated by newlines is easy
       "two-paragraphs.txt"         -> List(
         List("foo", "bar"),
         List("alpha", "bravo")
       )
-        .pipe(xxs => AsmBlock.interFlatMap(xxs)(List("", ""), identity))
-        .pipe(Line.mkString),
+        .pipe(xxs => AsmBlock.interFlatMap(xxs)(List("", ""), identity)),
       "feature-demo.asm"           -> FeatureDemo.program,
       "print-three-upper-math.asm" -> PrintThree.assemble(
         AssemblerOptions(InstructionCase.Uppercase, DefinitionsMode.UseDefinitionsWithMath)
@@ -53,6 +43,6 @@ object PrintPrograms extends ZIOAppDefault:
     for {
       // just a traverse in slow motion...
       _ <- programs
-             .map { case (f, s) => File(s"data/$f").writeLine(s) }
+             .map { case (f, xs) => File(s"data/$f").writeLines(xs) }
              .foldLeft[Task[Unit]](ZIO.unit)((acc, z) => acc *> z)
     } yield ()
diff --git a/firepower-demo/src/main/scala/com/htmlism/firepower/demo/PrintThree.scala b/firepower-demo/src/main/scala/com/htmlism/firepower/demo/PrintThree.scala
index 559eb1c..eb9dff1 100644
--- a/firepower-demo/src/main/scala/com/htmlism/firepower/demo/PrintThree.scala
+++ b/firepower-demo/src/main/scala/com/htmlism/firepower/demo/PrintThree.scala
@@ -28,11 +28,10 @@ object PrintThree:
   val program: List[Move[Easy6502.Color, Easy6502.Screen.Pixel]] =
     build(Easy6502.Screen(0x200))
 
-  def assemble(opts: AssemblerOptions): String =
+  def assemble(opts: AssemblerOptions): List[String] =
     (defines(opts.definitionsMode) ++ codes(opts.definitionsMode))
       .map(AsmBlock.toLines(opts.instructionCase))
       .pipe(xs => AsmBlock.interFlatMap(xs)(List("", ""), identity))
-      .pipe(str.Line.mkString)
 
   private def defines(opts: AssemblerOptions.DefinitionsMode) =
     opts match
diff --git a/firepower-demo/src/main/scala/com/htmlism/firepower/demo/SnakeEasy6502.scala b/firepower-demo/src/main/scala/com/htmlism/firepower/demo/SnakeEasy6502.scala
index a7bc090..56e9b24 100644
--- a/firepower-demo/src/main/scala/com/htmlism/firepower/demo/SnakeEasy6502.scala
+++ b/firepower-demo/src/main/scala/com/htmlism/firepower/demo/SnakeEasy6502.scala
@@ -5,8 +5,7 @@ import scala.util.chaining._
 import com.htmlism.firepower.core._
 
 object SnakeEasy6502:
-  def assemble(opts: AssemblerOptions): String =
+  def assemble(opts: AssemblerOptions): List[String] =
     (Nil)
       .map(AsmBlock.toLines(opts.instructionCase))
       .pipe(xs => AsmBlock.interFlatMap(xs)(List("", ""), identity))
-      .pipe(str.Line.mkString)
diff --git a/firepower-demo/src/main/scala/com/htmlism/firepower/demo/str/Line.scala b/firepower-demo/src/main/scala/com/htmlism/firepower/demo/str/Line.scala
deleted file mode 100644
index 4b9bafb..0000000
--- a/firepower-demo/src/main/scala/com/htmlism/firepower/demo/str/Line.scala
+++ /dev/null
@@ -1,6 +0,0 @@
-package com.htmlism.firepower.demo.str
-
-object Line:
-  def mkString(xs: List[String]): String =
-    xs
-      .mkString("\n")