Use target file name as disk label

src/main/scala/millfork/CompilationOptions.scala

@@ -5,7 +5,7 @@ import millfork.error.ErrorReporting
 /**
   * @author Karol Stasiak
   */
-case class CompilationOptions(platform: Platform, commandLineFlags: Map[CompilationFlag.Value, Boolean]) {
+case class CompilationOptions(platform: Platform, commandLineFlags: Map[CompilationFlag.Value, Boolean], outputFileName: Option[String]) {
 
   import CompilationFlag._
   import Cpu._

src/main/scala/millfork/Main.scala

@@ -73,7 +73,7 @@ object Main {
       ErrorReporting.info("No platform selected, defaulting to `c64`")
       "c64"
     })
-    val options = CompilationOptions(platform, c.flags)
+    val options = CompilationOptions(platform, c.flags, c.outputFileName)
     ErrorReporting.debug("Effective flags: ")
     options.flags.toSeq.sortBy(_._1).foreach{
       case (f, b) => ErrorReporting.debug(f"    $f%-30s : $b%s")

src/main/scala/millfork/output/AbstractAssembler.scala

@@ -177,6 +177,7 @@ abstract class AbstractAssembler[T <: AbstractCode](private val program: Program
     storeDecimalValueInNormalRespresentation(f(parseNormalToDecimalValue(a), parseNormalToDecimalValue(b)))
 
   def assemble(callGraph: CallGraph, optimizations: Seq[AssemblyOptimization[T]], options: CompilationOptions): AssemblerOutput = {
+    mem.programName = options.outputFileName.getOrElse("MILLFORK")
     val platform = options.platform
     val variableAllocators = platform.variableAllocators
     val zpOccupied = mem.banks("default").occupied

src/main/scala/millfork/output/CompiledMemory.scala

@@ -1,13 +1,12 @@
 package millfork.output
 
-import millfork.error.ErrorReporting
-
 import scala.collection.mutable
 
 /**
   * @author Karol Stasiak
   */
 class CompiledMemory(bankNames: List[String]) {
+  var programName = "MILLFORK"
   val banks = mutable.Map(bankNames.map(_ -> new MemoryBank): _*)
 }
 

src/main/scala/millfork/output/D88Output.scala

@@ -1,5 +1,7 @@
 package millfork.output
 
+import java.nio.charset.StandardCharsets
+
 import scala.collection.mutable
 
 /**
@@ -24,7 +26,7 @@ object D88Output extends OutputPackager {
   override def packageOutput(mem: CompiledMemory, bank: String): Array[Byte] = {
     val b = mem.banks(bank)
     val start = b.start
-    val header = new D88Header
+    val header = new D88Header(mem.programName.take(16))
     val trackList = new D88TrackList
     val sectors = mutable.ListBuffer[D88Sector]()
     var trackOffset = 688
@@ -67,13 +69,15 @@ sealed trait D88Part {
   def toArray: Array[Byte]
 }
 
-class D88Header extends D88Part {
+class D88Header(programName: String) extends D88Part {
   var totalSize: Long = 0
 
+  def isAlphanum(c: Char): Boolean = (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') || (c >= '0' && c <= '9')
+
   def toArray: Array[Byte] = {
-    Array(
-      'M', 'I', 'L', 'L', 'F', 'O', 'R', 'K',
-      0, 0, 0, 0, 0, 0, 0, 0,
+    programName.map(c =>
+      if (c == 0 || isAlphanum(c)) c.toByte else '_'.toByte
+    ).padTo(16, 0.toByte).toArray ++ Array(
       0, // NUL
       0, 0, 0, 0, 0, 0, 0, 0, 0, // reserved
       0, // not write protected