diff --git a/codeCore/src/prog8/code/core/Enumerations.kt b/codeCore/src/prog8/code/core/Enumerations.kt
index ca5f198e5..6bfc22461 100644
--- a/codeCore/src/prog8/code/core/Enumerations.kt
+++ b/codeCore/src/prog8/code/core/Enumerations.kt
@@ -145,7 +145,7 @@ class DataType private constructor(val base: BaseDataType, val sub: BaseDataType
             return if(splitwordarray && actualElementDt.isWord)
                 DataType(BaseDataType.ARRAY_SPLITW, actualElementDt, null)
             else {
-                if(actualElementDt.isNumericOrBool && actualElementDt != BaseDataType.LONG)
+                if(actualElementDt.isNumericOrBool)
                     DataType(BaseDataType.ARRAY, actualElementDt, null)
                 else
                     throw NoSuchElementException("invalid basic element dt $elementDt")
@@ -224,6 +224,7 @@ class DataType private constructor(val base: BaseDataType, val sub: BaseDataType
                 BaseDataType.WORD -> "word[]"
                 BaseDataType.UBYTE -> "ubyte[]"
                 BaseDataType.UWORD -> "uword[]"
+                BaseDataType.LONG -> "long[]"
                 else -> throw IllegalArgumentException("invalid sub type")
             }
         }
@@ -286,6 +287,7 @@ class DataType private constructor(val base: BaseDataType, val sub: BaseDataType
                 BaseDataType.BOOL -> "bool["
                 BaseDataType.BYTE -> "byte["
                 BaseDataType.WORD -> "@nosplit word["
+                BaseDataType.LONG -> "long["
                 BaseDataType.FLOAT -> "float["
                 else -> throw IllegalArgumentException("invalid sub type")
             }
@@ -365,6 +367,7 @@ class DataType private constructor(val base: BaseDataType, val sub: BaseDataType
     val isWordArray = base.isArray && !base.isPointerArray && (sub == BaseDataType.UWORD || sub == BaseDataType.WORD)
     val isUnsignedWordArray = base.isArray && !base.isPointerArray && sub == BaseDataType.UWORD
     val isSignedWordArray = base.isArray && !base.isPointerArray && sub == BaseDataType.WORD
+    val isLongArray = base.isArray && sub == BaseDataType.LONG
     val isFloatArray = base.isArray && !base.isPointerArray && sub == BaseDataType.FLOAT
     val isString = base == BaseDataType.STR
     val isBool = base == BaseDataType.BOOL
diff --git a/codeGenCpu6502/src/prog8/codegen/cpu6502/BuiltinFunctionsAsmGen.kt b/codeGenCpu6502/src/prog8/codegen/cpu6502/BuiltinFunctionsAsmGen.kt
index 90ea4fcf8..0fcc72bcc 100644
--- a/codeGenCpu6502/src/prog8/codegen/cpu6502/BuiltinFunctionsAsmGen.kt
+++ b/codeGenCpu6502/src/prog8/codegen/cpu6502/BuiltinFunctionsAsmGen.kt
@@ -27,8 +27,8 @@ internal class BuiltinFunctionsAsmGen(private val program: PtProgram,
         val sscope = fcall.definingISub()
 
         when (fcall.name) {
-            "lsw" -> throw AssemblyError("lsw() should have been removed or replaced by a const value")
-            "msw" -> throw AssemblyError("msw() should have been removed or replaced by a const value")
+            "msw" -> funcMsw(fcall, resultRegister)
+            "lsw" -> funcLsw(fcall, resultRegister)
             "msb" -> funcMsb(fcall, resultRegister)
             "lsb" -> funcLsb(fcall, resultRegister)
             "mkword" -> funcMkword(fcall, resultRegister)
@@ -1185,7 +1185,7 @@ internal class BuiltinFunctionsAsmGen(private val program: PtProgram,
     private fun funcMsb(fcall: PtBuiltinFunctionCall, resultRegister: RegisterOrPair?) {
         val arg = fcall.args.single()
         if (!arg.type.isWord)
-            throw AssemblyError("msb required word argument")
+            throw AssemblyError("msb requires word argument")
         if (arg is PtNumber)
             throw AssemblyError("msb(const) should have been const-folded away")
         if (arg is PtIdentifier) {
@@ -1371,6 +1371,53 @@ internal class BuiltinFunctionsAsmGen(private val program: PtProgram,
         }
     }
 
+    private fun funcMsw(fcall: PtBuiltinFunctionCall, resultRegister: RegisterOrPair?) {
+        val arg = fcall.args.single()
+        if (!arg.type.isLong)
+            throw AssemblyError("msw requires long argument")
+        if (arg is PtNumber)
+            throw AssemblyError("msw(const) should have been const-folded away")
+        if (arg is PtIdentifier) {
+            val sourceName = asmgen.asmVariableName(arg)
+            when(resultRegister) {
+                RegisterOrPair.AX -> asmgen.out("  lda  $sourceName+2 |  ldx  $sourceName+3")
+                null, RegisterOrPair.AY -> asmgen.out("  lda  $sourceName+2 |  ldy  $sourceName+3")
+                RegisterOrPair.XY -> asmgen.out("  ldx  $sourceName+2 |  ldy  $sourceName+3")
+                in Cx16VirtualRegisters -> {
+                    val regname = resultRegister.name.lowercase()
+                    asmgen.out("  lda  $sourceName+2 |  sta  cx16.$regname |  lda  $sourceName+3 |  sta  cx16.$regname+1")
+                }
+                else -> throw AssemblyError("invalid reg")
+            }
+        } else {
+            TODO("msw(expression) ${fcall.position} - use a temporary variable for now")
+        }
+    }
+
+    private fun funcLsw(fcall: PtBuiltinFunctionCall, resultRegister: RegisterOrPair?) {
+        val arg = fcall.args.single()
+        if (!arg.type.isLong)
+            throw AssemblyError("lsw requires long argument")
+        if (arg is PtNumber)
+            throw AssemblyError("lsw(const) should have been const-folded away")
+        if (arg is PtIdentifier) {
+            val sourceName = asmgen.asmVariableName(arg)
+            when(resultRegister) {
+                RegisterOrPair.AX -> asmgen.out("  lda  $sourceName |  ldx  $sourceName+1")
+                null, RegisterOrPair.AY -> asmgen.out("  lda  $sourceName |  ldy  $sourceName+1")
+                RegisterOrPair.XY -> asmgen.out("  ldx  $sourceName |  ldy  $sourceName+1")
+                in Cx16VirtualRegisters -> {
+                    val regname = resultRegister.name.lowercase()
+                    asmgen.out("  lda  $sourceName |  sta  cx16.$regname |  lda  $sourceName+1 |  sta  cx16.$regname+1")
+                }
+                else -> throw AssemblyError("invalid reg")
+            }
+        } else {
+            TODO("lsw(expression) ${fcall.position} - use a temporary variable for now")
+        }
+
+    }
+
     private fun translateArguments(call: PtBuiltinFunctionCall, scope: IPtSubroutine?) {
         val signature = BuiltinFunctions.getValue(call.name)
         val callConv = signature.callConvention(call.args.map {
diff --git a/codeGenCpu6502/src/prog8/codegen/cpu6502/ForLoopsAsmGen.kt b/codeGenCpu6502/src/prog8/codegen/cpu6502/ForLoopsAsmGen.kt
index 9e2f8952f..6dfa6006f 100644
--- a/codeGenCpu6502/src/prog8/codegen/cpu6502/ForLoopsAsmGen.kt
+++ b/codeGenCpu6502/src/prog8/codegen/cpu6502/ForLoopsAsmGen.kt
@@ -505,137 +505,158 @@ $endLabel""")
             is StMemVar -> symbol.length!!
             else -> 0u
         }
-        when {
-            iterableDt.isString -> {
-                if(asmgen.options.romable) {
-                    val indexVar = asmgen.createTempVarReused(BaseDataType.UBYTE, false, stmt)
-                    asmgen.out("""
+
+        fun iterateStrings() {
+            if(asmgen.options.romable) {
+                val indexVar = asmgen.createTempVarReused(BaseDataType.UBYTE, false, stmt)
+                asmgen.out("""
                         ldy  #0
                         sty  $indexVar
 $loopLabel              lda  $iterableName,y
                         beq  $endLabel
                         sta  ${asmgen.asmVariableName(stmt.variable)}""")
-                    asmgen.translate(stmt.statements)
-                    asmgen.out("""
+                asmgen.translate(stmt.statements)
+                asmgen.out("""
                         inc  $indexVar
                         ldy  $indexVar
                         bne  $loopLabel
 $endLabel""")
-                } else {
-                    val indexVar = asmgen.makeLabel("for_index")
-                    asmgen.out("""
+            } else {
+                val indexVar = asmgen.makeLabel("for_index")
+                asmgen.out("""
                         ldy  #0
                         sty  $indexVar
 $loopLabel              lda  $iterableName,y
                         beq  $endLabel
                         sta  ${asmgen.asmVariableName(stmt.variable)}""")
-                    asmgen.translate(stmt.statements)
-                    asmgen.out("""
+                asmgen.translate(stmt.statements)
+                asmgen.out("""
                         inc  $indexVar
                         ldy  $indexVar
                         bne  $loopLabel
 $indexVar   .byte  0                        
 $endLabel""")
-                }
             }
-            iterableDt.isByteArray || iterableDt.isBoolArray -> {
-                val indexVar = if(asmgen.options.romable)
-                    asmgen.createTempVarReused(iterableDt.elementType().base, false, stmt)
-                else
-                    asmgen.makeLabel("for_index")
-                asmgen.out("""
+        }
+
+        fun iterateBytes() {
+            val indexVar = if(asmgen.options.romable)
+                asmgen.createTempVarReused(iterableDt.elementType().base, false, stmt)
+            else
+                asmgen.makeLabel("for_index")
+            asmgen.out("""
                     ldy  #0
 $loopLabel          sty  $indexVar
                     lda  $iterableName,y
                     sta  ${asmgen.asmVariableName(stmt.variable)}""")
-                asmgen.translate(stmt.statements)
-                if(numElements<=255u) {
-                    asmgen.out("""
+            asmgen.translate(stmt.statements)
+            if(numElements<=255u) {
+                asmgen.out("""
                         ldy  $indexVar
                         iny
                         cpy  #$numElements
                         beq  $endLabel
                         bne  $loopLabel""")
-                } else {
-                    // length is 256
-                    asmgen.out("""
+            } else {
+                // length is 256
+                asmgen.out("""
                         ldy  $indexVar
                         iny
                         bne  $loopLabel
                         beq  $endLabel""")
-                }
-                if(!asmgen.options.romable) {
-                    if(numElements>=16u) {
-                        // allocate index var on ZP if possible, otherwise inline
-                        val result = zeropage.allocate(indexVar, DataType.UBYTE, null, stmt.position, asmgen.errors)
-                        result.fold(
-                            success = { (address, _, _)-> asmgen.out("""$indexVar = $address  ; auto zp UBYTE""") },
-                            failure = { asmgen.out("$indexVar    .byte  0") }
-                        )
-                    } else {
-                        asmgen.out("$indexVar    .byte  0")
-                    }
-                }
-                asmgen.out(endLabel)
             }
-            iterableDt.isSplitWordArray -> {
-                val indexVar = if(asmgen.options.romable)
-                    asmgen.createTempVarReused(BaseDataType.UBYTE, false, stmt)
-                else
-                    asmgen.makeLabel("for_index")
-                val loopvarName = asmgen.asmVariableName(stmt.variable)
-                asmgen.out("""
+            if(!asmgen.options.romable) {
+                if(numElements>=16u) {
+                    // allocate index var on ZP if possible, otherwise inline
+                    val result = zeropage.allocate(indexVar, DataType.UBYTE, null, stmt.position, asmgen.errors)
+                    result.fold(
+                        success = { (address, _, _)-> asmgen.out("""$indexVar = $address  ; auto zp UBYTE""") },
+                        failure = { asmgen.out("$indexVar    .byte  0") }
+                    )
+                } else {
+                    asmgen.out("$indexVar    .byte  0")
+                }
+            }
+            asmgen.out(endLabel)
+        }
+
+        fun iterateSplitWords() {
+            val indexVar = if(asmgen.options.romable)
+                asmgen.createTempVarReused(BaseDataType.UBYTE, false, stmt)
+            else
+                asmgen.makeLabel("for_index")
+            val loopvarName = asmgen.asmVariableName(stmt.variable)
+            asmgen.out("""
                     ldy  #0
 $loopLabel          sty  $indexVar
                     lda  ${iterableName}_lsb,y
                     sta  $loopvarName
                     lda  ${iterableName}_msb,y
                     sta  $loopvarName+1""")
-                asmgen.translate(stmt.statements)
-                if(numElements<=255u) {
-                    asmgen.out("""
+            asmgen.translate(stmt.statements)
+            if(numElements<=255u) {
+                asmgen.out("""
                         ldy  $indexVar
                         iny
                         cpy  #$numElements
                         beq  $endLabel
                         bne  $loopLabel""")
-                } else {
-                    // length is 256
-                    asmgen.out("""
+            } else {
+                // length is 256
+                asmgen.out("""
                         ldy  $indexVar
                         iny
                         bne  $loopLabel
                         beq  $endLabel""")
-                }
-                if(!asmgen.options.romable) {
-                    if(numElements>=16u) {
-                        // allocate index var on ZP if possible, otherwise inline
-                        val result = zeropage.allocate(indexVar, DataType.UBYTE, null, stmt.position, asmgen.errors)
-                        result.fold(
-                            success = { (address, _, _)-> asmgen.out("""$indexVar = $address  ; auto zp UBYTE""") },
-                            failure = { asmgen.out("$indexVar    .byte  0") }
-                        )
-                    } else {
-                        asmgen.out("$indexVar    .byte  0")
-                    }
-                }
-                asmgen.out(endLabel)
             }
-            iterableDt.isWordArray -> {
-                val indexVar = if(asmgen.options.romable)
-                    asmgen.createTempVarReused(BaseDataType.UBYTE, false, stmt)
-                else
-                    asmgen.makeLabel("for_index")
-                val loopvarName = asmgen.asmVariableName(stmt.variable)
-                asmgen.out("""
+            if(!asmgen.options.romable) {
+                if(numElements>=16u) {
+                    // allocate index var on ZP if possible, otherwise inline
+                    val result = zeropage.allocate(indexVar, DataType.UBYTE, null, stmt.position, asmgen.errors)
+                    result.fold(
+                        success = { (address, _, _)-> asmgen.out("""$indexVar = $address  ; auto zp UBYTE""") },
+                        failure = { asmgen.out("$indexVar    .byte  0") }
+                    )
+                } else {
+                    asmgen.out("$indexVar    .byte  0")
+                }
+            }
+            asmgen.out(endLabel)
+        }
+
+        fun iterateWords(actuallyLongs: Boolean = false) {
+            val indexVar = if(asmgen.options.romable)
+                asmgen.createTempVarReused(BaseDataType.UBYTE, false, stmt)
+            else
+                asmgen.makeLabel("for_index")
+            val loopvarName = asmgen.asmVariableName(stmt.variable)
+            asmgen.out("""
                     ldy  #0
 $loopLabel          sty  $indexVar
                     lda  $iterableName,y
                     sta  $loopvarName
                     lda  $iterableName+1,y
                     sta  $loopvarName+1""")
-                asmgen.translate(stmt.statements)
-                if(numElements<=127u) {
+            if(actuallyLongs) {
+                asmgen.out("""
+                    lda  $iterableName+2,y
+                    sta  $loopvarName+2
+                    lda  $iterableName+3,y
+                    sta  $loopvarName+3""")
+            }
+            asmgen.translate(stmt.statements)
+            if(numElements<=127u) {
+                if(actuallyLongs) {
+                    asmgen.out("""
+                        ldy  $indexVar
+                        iny
+                        iny
+                        iny
+                        iny
+                        cpy  #${numElements*4u}
+                        beq  $endLabel
+                        bne  $loopLabel""")
+                } else {
                     asmgen.out("""
                         ldy  $indexVar
                         iny
@@ -643,6 +664,19 @@ $loopLabel          sty  $indexVar
                         cpy  #${numElements*2u}
                         beq  $endLabel
                         bne  $loopLabel""")
+                }
+            } else {
+                if(actuallyLongs) {
+                    // array size is 64 longs, 256 bytes
+                    asmgen.out("""
+                        ldy  $indexVar
+                        iny
+                        iny
+                        iny
+                        iny
+                        bne  $loopLabel
+                        beq  $endLabel""")
+
                 } else {
                     // array size is 128 words, 256 bytes
                     asmgen.out("""
@@ -652,23 +686,29 @@ $loopLabel          sty  $indexVar
                         bne  $loopLabel
                         beq  $endLabel""")
                 }
-                if(!asmgen.options.romable) {
-                    if(numElements>=16u) {
-                        // allocate index var on ZP if possible, otherwise inline
-                        val result = zeropage.allocate(indexVar, DataType.UBYTE, null, stmt.position, asmgen.errors)
-                        result.fold(
-                            success = { (address, _, _)-> asmgen.out("""$indexVar = $address  ; auto zp UBYTE""") },
-                            failure = { asmgen.out("$indexVar    .byte  0") }
-                        )
-                    } else {
-                        asmgen.out("$indexVar    .byte  0")
-                    }
+            }
+            if(!asmgen.options.romable) {
+                if(numElements>=16u) {
+                    // allocate index var on ZP if possible, otherwise inline
+                    val result = zeropage.allocate(indexVar, DataType.UBYTE, null, stmt.position, asmgen.errors)
+                    result.fold(
+                        success = { (address, _, _)-> asmgen.out("""$indexVar = $address  ; auto zp UBYTE""") },
+                        failure = { asmgen.out("$indexVar    .byte  0") }
+                    )
+                } else {
+                    asmgen.out("$indexVar    .byte  0")
                 }
-                asmgen.out(endLabel)
-            }
-            iterableDt.isFloatArray -> {
-                throw AssemblyError("for loop with floating point variables is not supported")
             }
+            asmgen.out(endLabel)
+        }
+
+        when {
+            iterableDt.isString -> iterateStrings()
+            iterableDt.isByteArray || iterableDt.isBoolArray -> iterateBytes()
+            iterableDt.isSplitWordArray -> iterateSplitWords()
+            iterableDt.isWordArray -> iterateWords()
+            iterableDt.isLongArray -> iterateWords(true)
+            iterableDt.isFloatArray -> throw AssemblyError("for loop with floating point variables is not supported")
             else -> throw AssemblyError("can't iterate over $iterableDt")
         }
         asmgen.loopEndLabels.removeLast()
diff --git a/codeGenCpu6502/src/prog8/codegen/cpu6502/ProgramAndVarsGen.kt b/codeGenCpu6502/src/prog8/codegen/cpu6502/ProgramAndVarsGen.kt
index a792026c3..b93a69a70 100644
--- a/codeGenCpu6502/src/prog8/codegen/cpu6502/ProgramAndVarsGen.kt
+++ b/codeGenCpu6502/src/prog8/codegen/cpu6502/ProgramAndVarsGen.kt
@@ -901,6 +901,16 @@ internal class ProgramAndVarsGen(
                         asmgen.out("  .sint  " + chunk.joinToString())
                 }
             }
+            dt.isLongArray -> {
+                val data = makeArrayFillDataSigned(dt, value, orNumberOfZeros)
+                if (data.size <= 16)
+                    asmgen.out("$varname\t.dint  ${data.joinToString()}")
+                else {
+                    asmgen.out(varname)
+                    for (chunk in data.chunked(16))
+                        asmgen.out("  .dint  " + chunk.joinToString())
+                }
+            }
             dt.isFloatArray -> {
                 val array = value ?: zeroFilledArray(orNumberOfZeros!!)
                 val floatFills = array.map {
@@ -1023,7 +1033,7 @@ internal class ProgramAndVarsGen(
                 val number = it.number!!.toInt()
                 "$" + number.toString(16).padStart(4, '0')
             }
-            dt.isArray && dt.elementType().isSignedWord -> array.map {
+            dt.isSignedWordArray -> array.map {
                 val number = it.number!!.toInt()
                 val hexnum = number.absoluteValue.toString(16).padStart(4, '0')
                 if(number>=0)
@@ -1031,6 +1041,14 @@ internal class ProgramAndVarsGen(
                 else
                     "-$$hexnum"
             }
+            dt.isLongArray -> array.map {
+                val number = it.number!!.toInt()
+                val hexnum = number.absoluteValue.toString(16).padStart(8, '0')
+                if(number>=0)
+                    "$$hexnum"
+                else
+                    "-$$hexnum"
+            }
             else -> throw AssemblyError("invalid dt")
         }
     }
diff --git a/codeGenCpu6502/src/prog8/codegen/cpu6502/assignment/AssignmentAsmGen.kt b/codeGenCpu6502/src/prog8/codegen/cpu6502/assignment/AssignmentAsmGen.kt
index a15593f2d..3d237c889 100644
--- a/codeGenCpu6502/src/prog8/codegen/cpu6502/assignment/AssignmentAsmGen.kt
+++ b/codeGenCpu6502/src/prog8/codegen/cpu6502/assignment/AssignmentAsmGen.kt
@@ -3964,7 +3964,20 @@ $endLabel""")
                         stz  ${target.asmVarname}+2
                         stz  ${target.asmVarname}+3""")
                 }
-                TargetStorageKind.ARRAY -> TODO("assign long zero to array ${target.position}")
+                TargetStorageKind.ARRAY -> {
+                    val deref = target.array!!.pointerderef
+                    if(deref!=null) {
+                        pointergen.assignLong(IndexedPtrTarget(target), 0)
+                        return
+                    }
+                    asmgen.loadScaledArrayIndexIntoRegister(target.array, CpuRegister.Y)
+                    asmgen.out("""
+                        lda  #0
+                        sta  ${target.asmVarname},y
+                        sta  ${target.asmVarname}+1,y
+                        sta  ${target.asmVarname}+2,y
+                        sta  ${target.asmVarname}+3,y""")
+                }
                 TargetStorageKind.MEMORY -> throw AssemblyError("memory is bytes not long ${target.position}")
                 TargetStorageKind.REGISTER -> TODO("32 bits register assign? (we have no 32 bits registers right now) ${target.position}")
                 TargetStorageKind.POINTER -> throw AssemblyError("can't assign long to pointer, pointers are 16 bits ${target.position}")
@@ -3988,7 +4001,24 @@ $endLabel""")
                 store(hex.substring(2,4), 2)
                 store(hex.substring(0,2), 3)
             }
-            TargetStorageKind.ARRAY -> TODO("assign long $long to array ${target.position}")
+            TargetStorageKind.ARRAY -> {
+                val deref = target.array!!.pointerderef
+                if(deref!=null) {
+                    pointergen.assignWord(IndexedPtrTarget(target), long)
+                    return
+                }
+                asmgen.loadScaledArrayIndexIntoRegister(target.array, CpuRegister.Y)
+                val hex = long.toUInt().toString(16).padStart(8, '0')
+                asmgen.out("""
+                    lda  #$${hex.substring(6,8)}
+                    sta  ${target.asmVarname},y
+                    lda  #$${hex.substring(4, 6)}
+                    sta  ${target.asmVarname}+1,y
+                    lda  #$${hex.substring(2, 4)}
+                    sta  ${target.asmVarname}+2,y
+                    lda  #$${hex.take(2)}
+                    sta  ${target.asmVarname}+3,y""")
+            }
             TargetStorageKind.MEMORY -> throw AssemblyError("memory is bytes not long ${target.position}")
             TargetStorageKind.REGISTER -> TODO("32 bits register assign? (we have no 32 bits registers right now) ${target.position}")
             TargetStorageKind.POINTER -> throw AssemblyError("can't assign long to pointer, pointers are 16 bits ${target.position}")
@@ -4009,7 +4039,7 @@ $endLabel""")
                 TargetStorageKind.ARRAY -> {
                     val deref = target.array!!.pointerderef
                     if(deref!=null) {
-                        pointergen.assignWord(IndexedPtrTarget(target), word)
+                        pointergen.assignWord(IndexedPtrTarget(target), 0)
                         return
                     }
                     asmgen.loadScaledArrayIndexIntoRegister(target.array, CpuRegister.Y)
diff --git a/codeGenCpu6502/src/prog8/codegen/cpu6502/assignment/AugmentableAssignmentAsmGen.kt b/codeGenCpu6502/src/prog8/codegen/cpu6502/assignment/AugmentableAssignmentAsmGen.kt
index 41e78d193..0e642dd70 100644
--- a/codeGenCpu6502/src/prog8/codegen/cpu6502/assignment/AugmentableAssignmentAsmGen.kt
+++ b/codeGenCpu6502/src/prog8/codegen/cpu6502/assignment/AugmentableAssignmentAsmGen.kt
@@ -302,6 +302,25 @@ internal class AugmentableAssignmentAsmGen(private val program: PtProgram,
                             }
                         }
 
+                        target.datatype.isLong -> {
+                            when(value.kind) {
+                                SourceStorageKind.LITERALBOOLEAN -> inplacemodificationLongWithLiteralval(targetVarName, operator, value.boolean!!.asInt())
+                                SourceStorageKind.LITERALNUMBER -> inplacemodificationLongWithLiteralval(targetVarName, operator, value.number!!.number.toInt())
+                                SourceStorageKind.VARIABLE -> inplacemodificationLongWithVariable(targetVarName, operator, value.asmVarname)
+                                SourceStorageKind.REGISTER -> inplacemodificationLongWithVariable(targetVarName, operator, regName(value))
+                                SourceStorageKind.MEMORY -> TODO("inplace long modifiication ${target.position}")
+                                SourceStorageKind.ARRAY -> TODO("inplace long modifiication ${target.position}")
+                                SourceStorageKind.EXPRESSION -> {
+                                    if(value.expression is PtTypeCast) {
+                                        if (tryInplaceModifyWithRemovedRedundantCast(value.expression, target, operator)) return
+                                        TODO("inplace long modifiication ${target.position}")
+                                    } else {
+                                        TODO("inplace long modifiication ${target.position}")
+                                    }
+                                }
+                            }
+                        }
+
                         target.datatype.isFloat -> {
                             when(value.kind) {
                                 SourceStorageKind.LITERALBOOLEAN -> inplacemodificationFloatWithLiteralval(targetVarName, operator, value.boolean!!.asInt().toDouble())
diff --git a/codeGenCpu6502/src/prog8/codegen/cpu6502/assignment/PointerAssignmentsGen.kt b/codeGenCpu6502/src/prog8/codegen/cpu6502/assignment/PointerAssignmentsGen.kt
index 5ae58f6e3..200c15635 100644
--- a/codeGenCpu6502/src/prog8/codegen/cpu6502/assignment/PointerAssignmentsGen.kt
+++ b/codeGenCpu6502/src/prog8/codegen/cpu6502/assignment/PointerAssignmentsGen.kt
@@ -406,6 +406,10 @@ internal class PointerAssignmentsGen(private val asmgen: AsmGen6502Internal, pri
         TODO("array ptr assign const word ${target.position}")
     }
 
+    internal fun assignLong(target: IndexedPtrTarget, long: Int) {
+        TODO("array ptr assign const long ${target.position}")
+    }
+
     internal fun assignFloat(target: IndexedPtrTarget, float: Double) {
         TODO("array ptr assign const float ${target.position}")
     }
diff --git a/codeGenIntermediate/src/prog8/codegen/intermediate/BuiltinFuncGen.kt b/codeGenIntermediate/src/prog8/codegen/intermediate/BuiltinFuncGen.kt
index 797ac4925..efc247ac6 100644
--- a/codeGenIntermediate/src/prog8/codegen/intermediate/BuiltinFuncGen.kt
+++ b/codeGenIntermediate/src/prog8/codegen/intermediate/BuiltinFuncGen.kt
@@ -24,8 +24,8 @@ internal class BuiltinFuncGen(private val codeGen: IRCodeGen, private val exprGe
             "callfar" -> funcCallfar(call)
             "callfar2" -> funcCallfar2(call)
             "call" -> funcCall(call)
-            "lsw" -> throw AssemblyError("lsw() should have been removed or replaced by a const value")
-            "msw" -> throw AssemblyError("msw() should have been removed or replaced by a const value")
+            "msw" -> funcMsw(call)
+            "lsw" -> funcLsw(call)
             "msb" -> funcMsb(call)
             "lsb" -> funcLsb(call)
             "memory" -> funcMemory(call)
@@ -525,6 +525,15 @@ internal class BuiltinFuncGen(private val codeGen: IRCodeGen, private val exprGe
         return ExpressionCodeResult(result, IRDataType.BYTE, resultReg, -1)
     }
 
+    private fun funcLsw(call: PtBuiltinFunctionCall): ExpressionCodeResult {
+        val result = mutableListOf<IRCodeChunkBase>()
+        val tr = exprGen.translateExpression(call.args.single())
+        addToResult(result, tr, tr.resultReg, -1)
+        val resultReg = codeGen.registers.next(IRDataType.WORD)
+        addInstr(result, IRInstruction(Opcode.LSIG, IRDataType.WORD, reg1 = resultReg, reg2 = tr.resultReg), null)
+        return ExpressionCodeResult(result, IRDataType.WORD, resultReg, -1)
+    }
+
     private fun funcMsb(call: PtBuiltinFunctionCall): ExpressionCodeResult {
         val result = mutableListOf<IRCodeChunkBase>()
         val tr = exprGen.translateExpression(call.args.single())
@@ -535,6 +544,15 @@ internal class BuiltinFuncGen(private val codeGen: IRCodeGen, private val exprGe
         return ExpressionCodeResult(result, IRDataType.BYTE, resultReg, -1)
     }
 
+    private fun funcMsw(call: PtBuiltinFunctionCall): ExpressionCodeResult {
+        val result = mutableListOf<IRCodeChunkBase>()
+        val tr = exprGen.translateExpression(call.args.single())
+        addToResult(result, tr, tr.resultReg, -1)
+        val resultReg = codeGen.registers.next(IRDataType.WORD)
+        addInstr(result, IRInstruction(Opcode.MSIG, IRDataType.WORD, reg1 = resultReg, reg2 = tr.resultReg), null)
+        return ExpressionCodeResult(result, IRDataType.WORD, resultReg, -1)
+    }
+
     private fun funcRolRor(call: PtBuiltinFunctionCall): ExpressionCodeResult {
         val result = mutableListOf<IRCodeChunkBase>()
         val arg = call.args[0]
diff --git a/compiler/src/prog8/compiler/astprocessing/AstChecker.kt b/compiler/src/prog8/compiler/astprocessing/AstChecker.kt
index f4326c374..6d6cfed2d 100644
--- a/compiler/src/prog8/compiler/astprocessing/AstChecker.kt
+++ b/compiler/src/prog8/compiler/astprocessing/AstChecker.kt
@@ -240,6 +240,11 @@ internal class AstChecker(private val program: Program,
                             errors.err("word loop variable can only loop over bytes or words", forLoop.position)
                     }
 
+                    BaseDataType.LONG -> {
+                        if(!iterableDt.elementType().isInteger)
+                            errors.err("long loop variable can only loop over integers", forLoop.position)
+                    }
+
                     BaseDataType.FLOAT -> {
                         // Looping over float variables is very inefficient because the loopvar is going to
                         // get copied over with new values all the time. We don't support this for now.
@@ -941,6 +946,9 @@ internal class AstChecker(private val program: Program,
                         dt.isWordArray ->
                             if(arraySize > 128)
                                 err("regular word array length must be 1-128, use split array to get to 256")
+                        dt.isLongArray ->
+                            if(arraySize > 64)
+                                err("long array length must be 1-64")
                         dt.isFloatArray ->
                             if(arraySize > 51)
                                 err("float array length must be 1-51")
@@ -1044,6 +1052,10 @@ internal class AstChecker(private val program: Program,
                         if (length == 0 || length > 128)
                             err("regular word array length must be 1-128, use split array to get to 256")
                     }
+                    decl.datatype.isLongArray -> {
+                        if (length == 0 || length > 64)
+                            err("long array length must be 1-64")
+                    }
                     decl.datatype.isFloatArray -> {
                         if (length == 0 || length > 51)
                             err("float array length must be 1-51")
@@ -2478,7 +2490,6 @@ internal class AstChecker(private val program: Program,
     }
 
     override fun visit(onGoto: OnGoto) {
-        val t = onGoto.index.inferType(program)
         if(!onGoto.index.inferType(program).getOrUndef().isUnsignedByte) {
             errors.err("on..goto index must be an unsigned byte", onGoto.index.position)
         }
diff --git a/compiler/test/TestMemory.kt b/compiler/test/TestMemory.kt
index ecbfdac34..5a3125bd0 100644
--- a/compiler/test/TestMemory.kt
+++ b/compiler/test/TestMemory.kt
@@ -386,9 +386,6 @@ class TestMemory: FunSpec({
             shouldThrow<IllegalArgumentException> {
                 target.memorySize(BaseDataType.UNDEFINED)
             }
-            shouldThrow<NoSuchElementException> {
-                target.memorySize(DataType.arrayFor(BaseDataType.LONG), 10)
-            }
             target.memorySize(BaseDataType.BOOL) shouldBe 1
             target.memorySize(BaseDataType.BYTE) shouldBe 1
             target.memorySize(BaseDataType.WORD) shouldBe 2
@@ -397,6 +394,7 @@ class TestMemory: FunSpec({
 
             target.memorySize(DataType.BOOL, null) shouldBe 1
             target.memorySize(DataType.WORD, null) shouldBe 2
+            target.memorySize(DataType.LONG, null) shouldBe 4
             target.memorySize(DataType.FLOAT, null) shouldBe target.FLOAT_MEM_SIZE
 
             target.memorySize(DataType.STR, null) shouldBe 2
@@ -409,6 +407,7 @@ class TestMemory: FunSpec({
             target.memorySize(DataType.arrayFor(BaseDataType.BYTE), 10) shouldBe 10
             target.memorySize(DataType.arrayFor(BaseDataType.WORD), 10) shouldBe 20
             target.memorySize(DataType.arrayFor(BaseDataType.UWORD), 10) shouldBe 20
+            target.memorySize(DataType.arrayFor(BaseDataType.LONG), 10) shouldBe 40
             target.memorySize(DataType.arrayFor(BaseDataType.FLOAT), 10) shouldBe 10*target.FLOAT_MEM_SIZE
             target.memorySize(DataType.arrayFor(BaseDataType.WORD, true), 10) shouldBe 20
             target.memorySize(DataType.arrayFor(BaseDataType.UWORD, true), 10) shouldBe 20
diff --git a/compiler/test/ast/TestVariousCompilerAst.kt b/compiler/test/ast/TestVariousCompilerAst.kt
index aa5371601..c38647b8a 100644
--- a/compiler/test/ast/TestVariousCompilerAst.kt
+++ b/compiler/test/ast/TestVariousCompilerAst.kt
@@ -871,6 +871,7 @@ main {
         DataType.forDt(BaseDataType.FLOAT).isFloat shouldBe true
 
         DataType.arrayFor(BaseDataType.UBYTE, true).isUnsignedByteArray shouldBe true
+        DataType.arrayFor(BaseDataType.LONG).isLongArray shouldBe true
         DataType.arrayFor(BaseDataType.FLOAT).isFloatArray shouldBe true
         DataType.arrayFor(BaseDataType.UWORD).isUnsignedWordArray shouldBe true
         DataType.arrayFor(BaseDataType.UWORD).isArray shouldBe true
@@ -886,9 +887,6 @@ main {
         shouldThrow<NoSuchElementException> {
             DataType.arrayFor(BaseDataType.ARRAY)
         }
-        shouldThrow<NoSuchElementException> {
-            DataType.arrayFor(BaseDataType.LONG)
-        }
         shouldThrow<NoSuchElementException> {
             DataType.arrayFor(BaseDataType.UNDEFINED)
         }
diff --git a/examples/test.p8 b/examples/test.p8
index f51a01bb6..91eec9d99 100644
--- a/examples/test.p8
+++ b/examples/test.p8
@@ -14,6 +14,21 @@ main {
 ;    }
 
     sub start() {
+        long[] array = [-1999888777, -999, 42, 0, 77, 123456, 999999999]
+        long xx
+        for xx in array {
+            txt.print_uw(msw(xx))
+            txt.spc()
+            txt.print_uw(lsw(xx))
+            txt.nl()
+        }
+        txt.nl()
+        array[2] = 0
+        array[3] = 222222222
+        array[4] = bignum
+        array[5]++
+        array[6]--
+
         txt.print_l(-1999888777)
         txt.spc()
         txt.print_l(-999)
diff --git a/intermediate/src/prog8/intermediate/Utils.kt b/intermediate/src/prog8/intermediate/Utils.kt
index 6eefe8a6e..aafdc8b2d 100644
--- a/intermediate/src/prog8/intermediate/Utils.kt
+++ b/intermediate/src/prog8/intermediate/Utils.kt
@@ -32,6 +32,7 @@ fun DataType.irTypeString(length: UInt?): String {
                 BaseDataType.UWORD -> "uword[$lengthStr]"
                 BaseDataType.BYTE -> "byte[$lengthStr]"
                 BaseDataType.WORD -> "word[$lengthStr]"
+                BaseDataType.LONG -> "long[$lengthStr]"
                 BaseDataType.BOOL -> "bool[$lengthStr]"
                 BaseDataType.FLOAT -> "float[$lengthStr]"
                 else -> throw IllegalArgumentException("invalid sub type")
diff --git a/virtualmachine/src/prog8/vm/VmProgramLoader.kt b/virtualmachine/src/prog8/vm/VmProgramLoader.kt
index 15151db48..5738ff947 100644
--- a/virtualmachine/src/prog8/vm/VmProgramLoader.kt
+++ b/virtualmachine/src/prog8/vm/VmProgramLoader.kt
@@ -386,6 +386,17 @@ class VmProgramLoader {
                 }
             }
 
+            variable.dt.isLongArray -> {
+                for (elt in iElts) {
+                    val value = getInitializerValue(variable.dt, elt, symbolAddresses)
+                    value.fold(
+                        { memory.setSL(address, it.toInt()) },
+                        { throw IRParseException("didn't expect bool") }
+                    )
+                    address += 4
+                }
+            }
+
             variable.dt.isFloatArray -> {
                 for (elt in iElts) {
                     val value = getInitializerValue(variable.dt, elt, symbolAddresses)