version 5.4

implemented word bit shifts by variable number of bits.

compiler/res/prog8lib/c64/syslib.p8

@@ -269,6 +269,22 @@ asmsub  reset_system()  {
     }}
 }
 
+sub wait(uword jiffies) {
+    uword current_time = 0
+    c64.SETTIM(0,0,0)
+
+    while current_time < jiffies {
+        ; read clock
+        %asm {{
+            stx  P8ZP_SCRATCH_REG
+            jsr  c64.RDTIM
+            sta  current_time
+            stx  current_time+1
+            ldx  P8ZP_SCRATCH_REG
+        }}
+    }
+}
+
 asmsub  disable_runstop_and_charsetswitch() {
     %asm {{
         lda  #$80

compiler/res/prog8lib/c64/textio.p8

@@ -16,7 +16,7 @@ const ubyte DEFAULT_HEIGHT = 25
 
 
 sub  clear_screen() {
-    clear_screenchars(' ')
+    txt.chrout(147)
 }
 
 asmsub  fill_screen (ubyte char @ A, ubyte color @ Y) clobbers(A)  {

compiler/res/prog8lib/cx16/floats.p8

@@ -64,6 +64,7 @@ romsub $fe7e = FINLOG(byte value @A) clobbers (A, X, Y)           ; fac1 += sign
 romsub $fe81 = FOUT() clobbers(X) -> uword @ AY             ; fac1 -> string, address returned in AY
 romsub $fe8a = SQR() clobbers(A,X,Y)                        ; fac1 = SQRT(fac1)
 romsub $fe8d = FPWRT() clobbers(A,X,Y)                      ; fac1 = fac2 ** fac1
+; note: there is no FPWR() on the Cx16
 romsub $fe93 = NEGOP() clobbers(A)                          ; switch the sign of fac1
 romsub $fe96 = EXP() clobbers(A,X,Y)                        ; fac1 = EXP(fac1)  (e ** fac1)
 romsub $fe9f = RND2(byte value @A) clobbers(A,X,Y)                ; fac1 = RND(A) float random number generator

compiler/res/prog8lib/cx16/syslib.p8

@@ -220,7 +220,7 @@ romsub $ff08 = FB_get_pixels()  clobbers(A,X,Y)         ; uses ptr=r0, count=r1
 romsub $ff0b = FB_set_pixel(ubyte color @A)  clobbers(A,X,Y)
 romsub $ff0e = FB_set_pixels()  clobbers(A,X,Y)         ; uses ptr=r0, count=r1
 romsub $ff11 = FB_set_8_pixels(ubyte pattern @A, ubyte color @X)  clobbers(A,X,Y)
-romsub $ff14 = FB_set_8_pixels_opaque(ubyte pattern @A, ubyte color1 @X, ubyte color2 @Y)  clobbers(A,X,Y)  ; also uses mask=r0L
+romsub $ff14 = FB_set_8_pixels_opaque(ubyte mask @A, ubyte color1 @X, ubyte color2 @Y)  clobbers(A,X,Y)  ; also uses r0L=pattern
 romsub $ff17 = FB_fill_pixels(ubyte color @A)  clobbers(A,X,Y)   ; also uses count=r0, step=r1
 romsub $ff1a = FB_filter_pixels()  clobbers(A,X,Y)      ; uses ptr=r0, count=r1
 romsub $ff1d = FB_move_pixels()  clobbers(A,X,Y)        ; uses sx=r0, sy=r1, tx=r2, ty=r3, count=r4
@@ -245,7 +245,7 @@ romsub $fecc = monitor()  clobbers(A,X,Y)
 ; ---- end of kernal routines ----
 
 ; ---- utilities -----
-    asmsub vpeek(ubyte bank @A, uword address @XY) -> ubyte @A {
+asmsub vpeek(ubyte bank @A, uword address @XY) -> ubyte @A {
         ; -- get a byte from VERA's video memory
         ;    note: inefficient when reading multiple sequential bytes!
         %asm {{
@@ -257,9 +257,9 @@ romsub $fecc = monitor()  clobbers(A,X,Y)
                 lda  cx16.VERA_DATA0
                 rts
             }}
-    }
+}
 
-    sub vpoke(ubyte bank, uword address, ubyte value) {
+sub vpoke(ubyte bank, uword address, ubyte value) {
         ; -- write a single byte to VERA's video memory
         ;    note: inefficient when writing multiple sequential bytes!
         %asm {{
@@ -275,7 +275,59 @@ romsub $fecc = monitor()  clobbers(A,X,Y)
             sta  cx16.VERA_DATA0
             rts
         }}
+}
+
+sub FB_set_pixels_from_buf(uword buffer, uword count) {
+    %asm {{
+            ; -- This is replacement code for the normal FB_set_pixels subroutine in ROM
+            ;    However that routine contains a bug in the current v38 ROM that makes it crash when count > 255.
+            ;    So the code below replaces that. Once the ROM is patched this routine is no longer necessary.
+            ;    See https://github.com/commanderx16/x16-rom/issues/179
+            phx
+            lda  buffer
+            ldy  buffer+1
+            sta  P8ZP_SCRATCH_W1
+            sty  P8ZP_SCRATCH_W1+1
+            jsr  _pixels
+            plx
+            rts
+
+_pixels     lda  count+1
+            beq  +
+            ldx  #0
+-           jsr  _loop
+            inc  P8ZP_SCRATCH_W1+1
+            dec  count+1
+            bne  -
+
++           ldx  count
+_loop       ldy  #0
+-           lda  (P8ZP_SCRATCH_W1),y
+            sta  cx16.VERA_DATA0
+            iny
+            dex
+            bne  -
+            rts
+        }}
+}
+
+
+
+sub wait(uword jiffies) {
+    uword current_time = 0
+    c64.SETTIM(0,0,0)
+
+    while current_time < jiffies {
+        ; read clock
+        %asm {{
+            phx
+            jsr  c64.RDTIM
+            sta  current_time
+            stx  current_time+1
+            plx
+        }}
     }
+}
 
 
 ; ---- system stuff -----

compiler/res/prog8lib/cx16/textio.p8

@@ -16,7 +16,7 @@ const ubyte DEFAULT_HEIGHT = 60
 
 
 sub  clear_screen() {
-    clear_screenchars(' ')
+    txt.chrout(147)
 }
 
 asmsub  fill_screen (ubyte char @ A, ubyte color @ Y) clobbers(A)  {

compiler/res/prog8lib/diskio.p8

@@ -7,14 +7,14 @@ diskio {
 
 
     sub directory(ubyte drivenumber) -> ubyte {
-        ; -- Shows the directory contents of disk drive 8-11 (provide as argument). Returns success flag.
+        ; -- Prints the directory contents of disk drive 8-11 to the screen. Returns success.
 
         c64.SETNAM(1, "$")
-        c64.SETLFS(1, drivenumber, 0)
-        void c64.OPEN()          ; open 1,8,0,"$"
+        c64.SETLFS(13, drivenumber, 0)
+        void c64.OPEN()          ; open 13,8,0,"$"
         if_cs
             goto io_error
-        void c64.CHKIN(1)        ; use #1 as input channel
+        void c64.CHKIN(13)        ; use #13 as input channel
         if_cs
             goto io_error
 
@@ -39,14 +39,14 @@ diskio {
             void c64.CHRIN()
             status = c64.READST()
             void c64.STOP()
-            if_nz
+            if_z
                 break
         }
 
 io_error:
         status = c64.READST()
         c64.CLRCHN()        ; restore default i/o devices
-        c64.CLOSE(1)
+        c64.CLOSE(13)
 
         if status and status != 64 {            ; 64=end of file
             txt.print("\ni/o error, status: ")
@@ -59,33 +59,63 @@ io_error:
     }
 
 
-    ; internal variables for the iterative file lister
+    ; internal variables for the iterative file lister / loader
     ubyte list_suffixmatch
-    ubyte list_in_progress = false
     ubyte list_pattern_size
     ubyte list_skip_disk_name
     uword list_pattern
     uword list_blocks
-    str   list_filename = "????????????????"
+    ubyte iteration_in_progress = false
+    str   list_filename = "?" * 32
+
+
+    ; ----- get a list of files (uses iteration functions internally -----
+
+    sub list_files(ubyte drivenumber, uword pattern, ubyte suffixmatch, uword name_ptrs, ubyte max_names) -> ubyte {
+        ; -- fill the array 'name_ptrs' with (pointers to) the names of the files requested.
+        ubyte[256] names_buffer
+        ubyte[256] names_buffer1        ; to store a bit more names
+        uword buf_ptr = &names_buffer
+        ubyte files_found = 0
+        if lf_start_list(drivenumber, pattern, suffixmatch) {
+            while lf_next_entry() {
+                @(name_ptrs) = lsb(buf_ptr)
+                name_ptrs++
+                @(name_ptrs) = msb(buf_ptr)
+                name_ptrs++
+                buf_ptr += strcopy(diskio.list_filename, buf_ptr) + 1
+                files_found++
+                if buf_ptr - &names_buffer > (len(names_buffer) + len(names_buffer1) - 18)
+                    break
+                if files_found == max_names
+                    break
+            }
+            lf_end_list()
+        }
+        return files_found
+    }
+
+    ; ----- iterative file lister functions -----
 
     sub lf_start_list(ubyte drivenumber, uword pattern, ubyte suffixmatch) -> ubyte {
         ; -- start an iterative file listing with optional prefix or suffix name matching.
+        ;    note: only a single iteration loop can be active at a time!
         lf_end_list()
         list_pattern = pattern
         list_suffixmatch = suffixmatch
         list_skip_disk_name = true
-        list_in_progress = true
+        iteration_in_progress = true
         if pattern==0
             list_pattern_size = 0
         else
             list_pattern_size = strlen(pattern)
 
         c64.SETNAM(1, "$")
-        c64.SETLFS(1, drivenumber, 0)
-        void c64.OPEN()          ; open 1,8,0,"$"
+        c64.SETLFS(12, drivenumber, 0)
+        void c64.OPEN()          ; open 12,8,0,"$"
         if_cs
             goto io_error
-        void c64.CHKIN(1)        ; use #1 as input channel
+        void c64.CHKIN(12)        ; use #12 as input channel
         if_cs
             goto io_error
 
@@ -106,13 +136,19 @@ io_error:
         ;    results will be found in list_blocks and list_filename.
         ;    if it returns false though, there are no more entries (or an error occurred).
 
-        if not list_in_progress
+        if not iteration_in_progress
             return false
 
-        while not c64.READST() {
+        repeat {
+            void c64.CHKIN(12)        ; use #12 as input channel again
+
             uword nameptr = &list_filename
             ubyte blocks_lsb = c64.CHRIN()
             ubyte blocks_msb = c64.CHRIN()
+
+            if c64.READST()
+                goto close_end
+
             list_blocks = mkword(blocks_msb, blocks_lsb)
 
             ; read until the filename starts after the first "
@@ -163,16 +199,67 @@ close_end:
 
     sub lf_end_list() {
         ; -- end an iterative file listing session (close channels).
-        if list_in_progress {
+        if iteration_in_progress {
             c64.CLRCHN()
-            c64.CLOSE(1)
-            list_in_progress = false
+            c64.CLOSE(12)
+            iteration_in_progress = false
         }
     }
 
 
-    sub status(ubyte drivenumber) {
-        ; -- display the disk drive's current status message
+    ; ----- iterative file loader functions -----
+
+    sub f_open(ubyte drivenumber, uword filenameptr) -> ubyte {
+        ; -- open a file for iterative reading with f_read
+        ;    note: only a single iteration loop can be active at a time!
+        f_close()
+
+        c64.SETNAM(strlen(filenameptr), filenameptr)
+        c64.SETLFS(11, drivenumber, 0)
+        void c64.OPEN()          ; open 11,8,0,"filename"
+        if_cc {
+            iteration_in_progress = true
+            void c64.CHKIN(11)        ; use #11 as input channel
+            if_cc
+                return true
+        }
+        f_close()
+        return false
+    }
+
+    sub f_read(uword bufferpointer, uword buffersize) -> uword {
+        if not iteration_in_progress
+            return 0
+
+        uword actual = 0
+        void c64.CHKIN(11)        ; use #11 as input channel again
+        repeat buffersize {
+            ubyte data = c64.CHRIN()
+            @(bufferpointer) = data
+            bufferpointer++
+            actual++
+            ubyte status = c64.READST()
+            if status==64
+                f_close()       ; end of file, close it
+            if status
+                return actual
+        }
+        return actual
+    }
+
+    sub f_close() {
+        ; -- end an iterative file loading session (close channels).
+        if iteration_in_progress {
+            c64.CLRCHN()
+            c64.CLOSE(11)
+            iteration_in_progress = false
+        }
+    }
+
+
+    sub status(ubyte drivenumber) -> uword {
+        ; -- retrieve the disk drive's current status message
+        uword messageptr = &filename
         c64.SETNAM(0, filename)
         c64.SETLFS(15, drivenumber, 15)
         void c64.OPEN()          ; open 15,8,15
@@ -182,12 +269,16 @@ close_end:
         if_cs
             goto io_error
 
-        while not c64.READST()
-            txt.chrout(c64.CHRIN())
+        while not c64.READST() {
+            @(messageptr) = c64.CHRIN()
+            messageptr++
+        }
 
 io_error:
+        @(messageptr) = 0
         c64.CLRCHN()        ; restore default i/o devices
         c64.CLOSE(15)
+        return filename
     }
 
 

compiler/res/prog8lib/math.asm

@@ -1352,6 +1352,33 @@ shift_left_w_3	.proc
 		jmp  shift_left_w_7._shift3
 		.pend
 
+
+shift_left_w	.proc
+		; -- variable number of shifts left
+		inx
+		ldy  P8ESTACK_LO,x
+		bne  _shift
+		rts
+_shift		asl  P8ESTACK_LO+1,x
+		rol  P8ESTACK_HI+1,x
+		dey
+		bne  _shift
+		rts
+		.pend
+
+shift_right_uw	.proc
+		; -- uword variable number of shifts right
+		inx
+		ldy  P8ESTACK_LO,x
+		bne  _shift
+		rts
+_shift		lsr  P8ESTACK_HI+1,x
+		ror  P8ESTACK_LO+1,x
+		dey
+		bne  _shift
+		rts
+		.pend
+
 shift_right_uw_7	.proc
 		lda  P8ESTACK_LO+1,x
 		sta  P8ZP_SCRATCH_B1
@@ -1482,6 +1509,21 @@ shift_right_w_3	.proc
 		.pend
 
 
+shift_right_w	.proc
+		; -- signed word variable number of shifts right
+		inx
+		ldy  P8ESTACK_LO,x
+		bne  _shift
+		rts
+_shift		lda  P8ESTACK_HI+1,x
+		asl  a
+		ror  P8ESTACK_HI+1,x
+		ror  P8ESTACK_LO+1,x
+		dey
+		bne  _shift
+		rts
+		.pend
+
 
 ; support for bit shifting that is too large to be unrolled:
 

compiler/res/prog8lib/prog8_funcs.asm

@@ -1346,3 +1346,24 @@ func_strcmp_stack	.proc
 		dex
 		rts
 		.pend
+
+func_strcopy	.proc
+		lda  _arg_to
+		ldy  _arg_to+1
+		sta  P8ZP_SCRATCH_W1
+		sty  P8ZP_SCRATCH_W1+1
+		lda  _arg_from
+		ldy  _arg_from+1
+		jsr  strcpy
+		tya
+		rts
+_arg_from	.word  0
+_arg_to		.word  0
+		.pend
+
+func_strcopy_to_stack	.proc
+		jsr  func_strcopy
+		sta  P8ESTACK_LO,x
+		dex
+		rts
+		.pend

compiler/res/prog8lib/prog8_lib.asm

@@ -993,6 +993,7 @@ _arg_index	.byte  0
 strcpy		.proc
 		; copy a string (must be 0-terminated) from A/Y to (P8ZP_SCRATCH_W1)
 		; it is assumed the target string is large enough.
+		; returns the length of the string that was copied in Y.
 		sta  P8ZP_SCRATCH_W2
 		sty  P8ZP_SCRATCH_W2+1
 		ldy  #$ff

compiler/res/version.txt

@@ -1 +1 @@
-5.3
+5.4

compiler/src/prog8/ast/processing/StatementReorderer.kt

@@ -4,6 +4,7 @@ import prog8.ast.*
 import prog8.ast.base.*
 import prog8.ast.expressions.*
 import prog8.ast.statements.*
+import prog8.functions.BuiltinFunctions
 
 
 internal class StatementReorderer(val program: Program, val errors: ErrorReporter) : AstWalker() {
@@ -91,6 +92,55 @@ internal class StatementReorderer(val program: Program, val errors: ErrorReporte
         }
     }
 
+    override fun after(expr: BinaryExpression, parent: Node): Iterable<IAstModification> {
+        // when using a simple bit shift and assigning it to a variable of a different type,
+        // try to make the bit shifting 'wide enough' to fall into the variable's type.
+        // with this, for instance, uword x = 1 << 10  will result in 1024 rather than 0 (the ubyte result).
+        if(expr.operator=="<<" || expr.operator==">>") {
+            val leftDt = expr.left.inferType(program)
+            when (parent) {
+                is Assignment -> {
+                    val targetDt = parent.target.inferType(program)
+                    if(leftDt != targetDt) {
+                        val cast = TypecastExpression(expr.left, targetDt.typeOrElse(DataType.STRUCT), true, parent.position)
+                        return listOf(IAstModification.ReplaceNode(expr.left, cast, expr))
+                    }
+                }
+                is VarDecl -> {
+                    if(!leftDt.istype(parent.datatype)) {
+                        val cast = TypecastExpression(expr.left, parent.datatype, true, parent.position)
+                        return listOf(IAstModification.ReplaceNode(expr.left, cast, expr))
+                    }
+                }
+                is IFunctionCall -> {
+                    val argnum = parent.args.indexOf(expr)
+                    when (val callee = parent.target.targetStatement(program.namespace)) {
+                        is Subroutine -> {
+                            val paramType = callee.parameters[argnum].type
+                            if(leftDt isAssignableTo paramType) {
+                                val cast = TypecastExpression(expr.left, paramType, true, parent.position)
+                                return listOf(IAstModification.ReplaceNode(expr.left, cast, expr))
+                            }
+                        }
+                        is BuiltinFunctionStatementPlaceholder -> {
+                            val func = BuiltinFunctions.getValue(callee.name)
+                            val paramTypes = func.parameters[argnum].possibleDatatypes
+                            for(type in paramTypes) {
+                                if(leftDt isAssignableTo type) {
+                                    val cast = TypecastExpression(expr.left, type, true, parent.position)
+                                    return listOf(IAstModification.ReplaceNode(expr.left, cast, expr))
+                                }
+                            }
+                        }
+                        else -> throw FatalAstException("weird callee")
+                    }
+                }
+                else -> return noModifications
+            }
+        }
+        return noModifications
+    }
+
     private fun getAutoIndexerVarFor(expr: ArrayIndexedExpression): MutableList<IAstModification> {
         val modifications = mutableListOf<IAstModification>()
         val subroutine = expr.definingSubroutine()!!

compiler/src/prog8/compiler/target/c64/codegen/AsmGen.kt

@@ -160,6 +160,7 @@ internal class AsmGen(private val program: Program,
             val floatvalue = flt.key
             out("${flt.value}\t.byte  $floatFill  ; float $floatvalue")
         }
+        out("prog8_program_end\t; end of program label for progend()")
     }
 
     private fun block2asm(block: Block) {

compiler/src/prog8/compiler/target/c64/codegen/BuiltinFunctionsAsmGen.kt

@@ -5,10 +5,7 @@ import prog8.ast.Node
 import prog8.ast.Program
 import prog8.ast.base.*
 import prog8.ast.expressions.*
-import prog8.ast.statements.ArrayIndex
-import prog8.ast.statements.DirectMemoryWrite
-import prog8.ast.statements.FunctionCallStatement
-import prog8.ast.statements.Subroutine
+import prog8.ast.statements.*
 import prog8.compiler.AssemblyError
 import prog8.compiler.target.CompilationTarget
 import prog8.compiler.target.Cx16Target
@@ -84,6 +81,13 @@ internal class BuiltinFunctionsAsmGen(private val program: Program, private val
             "set_irqd" -> asmgen.out("  sei")
             "strlen" -> funcStrlen(fcall, resultToStack)
             "strcmp" -> funcStrcmp(fcall, func, resultToStack, scope)
+            "strcopy" -> {
+                translateArguments(fcall.args, func, scope)
+                if(resultToStack)
+                    asmgen.out("  jsr  prog8_lib.func_strcopy_to_stack")
+                else
+                    asmgen.out("  jsr  prog8_lib.func_strcopy")
+            }
             "memcopy", "memset", "memsetw" -> funcMemSetCopy(fcall, func, scope)
             "substr", "leftstr", "rightstr" -> {
                 translateArguments(fcall.args, func, scope)
@@ -93,6 +97,17 @@ internal class BuiltinFunctionsAsmGen(private val program: Program, private val
                 translateArguments(fcall.args, func, scope)
                 asmgen.out("  jmp  prog8_lib.func_exit")
             }
+            "progend" -> {
+                if(resultToStack)
+                    asmgen.out("""
+                        lda  #<prog8_program_end
+                        sta  P8ESTACK_LO,x
+                        lda  #>prog8_program_end
+                        sta  P8ESTACK_HI,x
+                        dex""")
+                else
+                    asmgen.out("  lda  #<prog8_program_end |  ldy  #>prog8_program_end")
+            }
             else -> TODO("missing asmgen for builtin func ${func.name}")
         }
     }
@@ -532,14 +547,21 @@ internal class BuiltinFunctionsAsmGen(private val program: Program, private val
     }
 
     private fun funcStrlen(fcall: IFunctionCall, resultToStack: Boolean) {
-        val name = asmgen.asmVariableName(fcall.args[0] as IdentifierReference)
-        val type = fcall.args[0].inferType(program)
-        when {
-            type.istype(DataType.STR) -> asmgen.out("  lda  #<$name |  ldy  #>$name")
-            type.istype(DataType.UWORD) -> asmgen.out("  lda  $name |  ldy  $name+1")
-            else -> throw AssemblyError("strlen requires str or uword arg")
+        if (fcall.args[0] is IdentifierReference) {
+            // use the address of the variable
+            val name = asmgen.asmVariableName(fcall.args[0] as IdentifierReference)
+            val type = fcall.args[0].inferType(program)
+            when {
+                type.istype(DataType.STR) -> asmgen.out("  lda  #<$name |  ldy  #>$name")
+                type.istype(DataType.UWORD) -> asmgen.out("  lda  $name |  ldy  $name+1")
+                else -> throw AssemblyError("strlen requires str or uword arg")
+            }
         }
-        if(resultToStack)
+        else {
+            // use the expression value as address of the string
+            asmgen.assignExpressionToRegister(fcall.args[0], RegisterOrPair.AY)
+        }
+        if (resultToStack)
             asmgen.out("  jsr  prog8_lib.func_strlen_stack")
         else
             asmgen.out("  jsr  prog8_lib.func_strlen_into_A")

compiler/src/prog8/compiler/target/c64/codegen/ExpressionsAsmGen.kt

@@ -1947,24 +1947,29 @@ internal class ExpressionsAsmGen(private val program: Program, private val asmge
         }
     }
 
-    private fun translateBinaryOperatorWords(operator: String, types: DataType) {
+    private fun translateBinaryOperatorWords(operator: String, dt: DataType) {
         when(operator) {
             "**" -> throw AssemblyError("** operator requires floats")
             "*" -> asmgen.out("  jsr  prog8_lib.mul_word")
-            "/" -> asmgen.out(if(types==DataType.UWORD) "  jsr  prog8_lib.idiv_uw" else "  jsr  prog8_lib.idiv_w")
+            "/" -> asmgen.out(if(dt==DataType.UWORD) "  jsr  prog8_lib.idiv_uw" else "  jsr  prog8_lib.idiv_w")
             "%" -> {
-                if(types==DataType.WORD)
+                if(dt==DataType.WORD)
                     throw AssemblyError("remainder of signed integers is not properly defined/implemented, use unsigned instead")
                 asmgen.out("  jsr prog8_lib.remainder_uw")
             }
             "+" -> asmgen.out("  jsr  prog8_lib.add_w")
             "-" -> asmgen.out("  jsr  prog8_lib.sub_w")
-            "<<" -> throw AssemblyError("<< should not operate via stack")
-            ">>" -> throw AssemblyError(">> should not operate via stack")
-            "<" -> asmgen.out(if(types==DataType.UWORD) "  jsr  prog8_lib.less_uw" else "  jsr  prog8_lib.less_w")
-            ">" -> asmgen.out(if(types==DataType.UWORD) "  jsr  prog8_lib.greater_uw" else "  jsr  prog8_lib.greater_w")
-            "<=" -> asmgen.out(if(types==DataType.UWORD) "  jsr  prog8_lib.lesseq_uw" else "  jsr  prog8_lib.lesseq_w")
-            ">=" -> asmgen.out(if(types==DataType.UWORD) "  jsr  prog8_lib.greatereq_uw" else "  jsr  prog8_lib.greatereq_w")
+            "<<" -> asmgen.out("  jsr  math.shift_left_w")
+            ">>" -> {
+                if(dt==DataType.UWORD)
+                    asmgen.out("  jsr  math.shift_right_uw")
+                else
+                    asmgen.out("  jsr  math.shift_right_w")
+            }
+            "<" -> asmgen.out(if(dt==DataType.UWORD) "  jsr  prog8_lib.less_uw" else "  jsr  prog8_lib.less_w")
+            ">" -> asmgen.out(if(dt==DataType.UWORD) "  jsr  prog8_lib.greater_uw" else "  jsr  prog8_lib.greater_w")
+            "<=" -> asmgen.out(if(dt==DataType.UWORD) "  jsr  prog8_lib.lesseq_uw" else "  jsr  prog8_lib.lesseq_w")
+            ">=" -> asmgen.out(if(dt==DataType.UWORD) "  jsr  prog8_lib.greatereq_uw" else "  jsr  prog8_lib.greatereq_w")
             "==" -> asmgen.out("  jsr  prog8_lib.equal_w")
             "!=" -> asmgen.out("  jsr  prog8_lib.notequal_w")            "&" -> asmgen.out("  jsr  prog8_lib.bitand_w")
             "^" -> asmgen.out("  jsr  prog8_lib.bitxor_w")

compiler/src/prog8/compiler/target/c64/codegen/FunctionCallAsmGen.kt

@@ -20,7 +20,7 @@ internal class FunctionCallAsmGen(private val program: Program, private val asmg
         translateFunctionCall(stmt, preserveStatusRegisterAfterCall)
         // functioncalls no longer return results on the stack, so simply ignore the results in the registers
         if(preserveStatusRegisterAfterCall)
-            asmgen.out("  plp\t; restore status flags from call")
+            asmgen.out("  plp")     // restore status flags from call
     }
 
 
@@ -69,7 +69,7 @@ internal class FunctionCallAsmGen(private val program: Program, private val asmg
         asmgen.out("  jsr  $subName")
 
         if(preserveStatusRegisterAfterCall) {
-            asmgen.out("  php\t; save status flags from call")
+            asmgen.out("  php")    // save status flags from call
             // note: the containing statement (such as the FunctionCallStatement or the Assignment or the Expression)
             //       must take care of popping this value again at the end!
         }

compiler/src/prog8/compiler/target/c64/codegen/assignment/AssignmentAsmGen.kt

@@ -183,7 +183,7 @@ internal class AssignmentAsmGen(private val program: Program, private val asmgen
                                     }
                                 }
                                 if (preserveStatusRegisterAfterCall)
-                                    asmgen.out("  plp\t; restore status flags from call")
+                                    asmgen.out("  plp")   // restore status flags from call
                             }
                             is BuiltinFunctionStatementPlaceholder -> {
                                 val signature = BuiltinFunctions.getValue(sub.name)

compiler/src/prog8/compiler/target/c64/codegen/assignment/AugmentableAssignmentAsmGen.kt

@@ -7,6 +7,7 @@ import prog8.ast.statements.Subroutine
 import prog8.compiler.AssemblyError
 import prog8.compiler.target.CompilationTarget
 import prog8.compiler.target.CpuType
+import prog8.compiler.target.Cx16Target
 import prog8.compiler.target.c64.codegen.AsmGen
 import prog8.compiler.target.c64.codegen.ExpressionsAsmGen
 import prog8.compiler.toHex
@@ -317,9 +318,10 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                     bne  -
 +""")
             }
-            "&" -> asmgen.out(" and  P8ZP_SCRATCH_B1")
-            "^" -> asmgen.out(" eor  P8ZP_SCRATCH_B1")
-            "|" -> asmgen.out(" ora  P8ZP_SCRATCH_B1")
+            "&", "and" -> asmgen.out(" and  P8ZP_SCRATCH_B1")
+            "|", "or" -> asmgen.out(" ora  P8ZP_SCRATCH_B1")
+            "^", "xor" -> asmgen.out(" eor  P8ZP_SCRATCH_B1")
+            in comparisonOperators -> TODO("in-place modification for $operator")
             else -> throw AssemblyError("invalid operator for in-place modification $operator")
         }
         if(ptrOnZp)
@@ -357,9 +359,10 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                         bne  -
 +""")
             }
-            "&" -> asmgen.out(" and  $otherName")
-            "^" -> asmgen.out(" eor  $otherName")
-            "|" -> asmgen.out(" ora  $otherName")
+            "&", "and" -> asmgen.out(" and  $otherName")
+            "|", "or" -> asmgen.out(" ora  $otherName")
+            "^", "xor" -> asmgen.out(" eor  $otherName")
+            in comparisonOperators -> TODO("in-place modification for $operator")
             else -> throw AssemblyError("invalid operator for in-place modification $operator")
         }
         if(ptrOnZp)
@@ -438,7 +441,7 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                         asmgen.out("  sta  (P8ZP_SCRATCH_W1),y")
                 }
             }
-            "&" -> {
+            "&", "and" -> {
                 val (ptrOnZp, sourceName) = asmgen.loadByteFromPointerIntoA(pointervar)
                 asmgen.out(" and  #$value")
                 if(ptrOnZp)
@@ -446,15 +449,7 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                 else
                     asmgen.out("  sta  (P8ZP_SCRATCH_W1),y")
             }
-            "^" -> {
-                val (ptrOnZp, sourceName) = asmgen.loadByteFromPointerIntoA(pointervar)
-                asmgen.out(" eor  #$value")
-                if(ptrOnZp)
-                    asmgen.out("  sta  ($sourceName),y")
-                else
-                    asmgen.out("  sta  (P8ZP_SCRATCH_W1),y")
-            }
-            "|" -> {
+            "|", "or" -> {
                 val (ptrOnZp, sourceName) = asmgen.loadByteFromPointerIntoA(pointervar)
                 asmgen.out(" ora  #$value")
                 if(ptrOnZp)
@@ -462,6 +457,15 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                 else
                     asmgen.out("  sta  (P8ZP_SCRATCH_W1),y")
             }
+            "^", "xor" -> {
+                val (ptrOnZp, sourceName) = asmgen.loadByteFromPointerIntoA(pointervar)
+                asmgen.out(" eor  #$value")
+                if(ptrOnZp)
+                    asmgen.out("  sta  ($sourceName),y")
+                else
+                    asmgen.out("  sta  (P8ZP_SCRATCH_W1),y")
+            }
+            in comparisonOperators -> TODO("in-place modification for $operator")
             else -> throw AssemblyError("invalid operator for in-place modification $operator")
         }
     }
@@ -525,18 +529,19 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
 +""")
                 }
             }
-            "&" -> {
+            "&", "and" -> {
                 asmgen.assignExpressionToRegister(value, RegisterOrPair.A)
                 asmgen.out("  and  $name |  sta  $name")
             }
-            "^" -> {
-                asmgen.assignExpressionToRegister(value, RegisterOrPair.A)
-                asmgen.out("  eor  $name |  sta  $name")
-            }
-            "|" -> {
+            "|", "or" -> {
                 asmgen.assignExpressionToRegister(value, RegisterOrPair.A)
                 asmgen.out("  ora  $name |  sta  $name")
             }
+            "^", "xor" -> {
+                asmgen.assignExpressionToRegister(value, RegisterOrPair.A)
+                asmgen.out("  eor  $name |  sta  $name")
+            }
+            in comparisonOperators -> TODO("in-place modification for $operator")
             else -> throw AssemblyError("invalid operator for in-place modification $operator")
         }
     }
@@ -591,27 +596,10 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
 +""")
                 }
             }
-            "&" -> asmgen.out(" lda  $name |  and  $otherName |  sta  $name")
-            "^" -> asmgen.out(" lda  $name |  eor  $otherName |  sta  $name")
-            "|" -> asmgen.out(" lda  $name |  ora  $otherName |  sta  $name")
-            "and" -> asmgen.out("""
-                lda  $name
-                and  $otherName
-                beq  +
-                lda  #1
-+               sta  $name""")
-            "or" -> asmgen.out("""
-                lda  $name
-                ora  $otherName
-                beq  +
-                lda  #1
-+               sta  $name""")
-            "xor" -> asmgen.out("""
-                lda  $name
-                eor  $otherName
-                beq  +
-                lda  #1
-+               sta  $name""")
+            "&", "and" -> asmgen.out(" lda  $name |  and  $otherName |  sta  $name")
+            "|", "or" -> asmgen.out(" lda  $name |  ora  $otherName |  sta  $name")
+            "^", "xor" -> asmgen.out(" lda  $name |  eor  $otherName |  sta  $name")
+            in comparisonOperators -> TODO("in-place modification for $operator")
             else -> throw AssemblyError("invalid operator for in-place modification $operator")
         }
     }
@@ -680,9 +668,10 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                     }
                 }
             }
-            "&" -> asmgen.out(" lda  $name |  and  #$value |  sta  $name")
-            "^" -> asmgen.out(" lda  $name |  eor  #$value |  sta  $name")
-            "|" -> asmgen.out(" lda  $name |  ora  #$value |  sta  $name")
+            "&", "and" -> asmgen.out(" lda  $name |  and  #$value |  sta  $name")
+            "|", "or" -> asmgen.out(" lda  $name |  ora  #$value |  sta  $name")
+            "^", "xor" -> asmgen.out(" lda  $name |  eor  #$value |  sta  $name")
+            in comparisonOperators -> TODO("in-place modification for $operator")
             else -> throw AssemblyError("invalid operator for in-place modification $operator")
         }
     }
@@ -949,7 +938,7 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                     }
                 }
             }
-            "&" -> {
+            "&", "and" -> {
                 when {
                     value == 0 -> {
                         if(CompilationTarget.instance.machine.cpu == CpuType.CPU65c02)
@@ -974,15 +963,7 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                     else -> asmgen.out("  lda  $name |  and  #<$value |  sta  $name |  lda  $name+1 |  and  #>$value |  sta  $name+1")
                 }
             }
-            "^" -> {
-                when {
-                    value == 0 -> {}
-                    value and 255 == 0 -> asmgen.out("  lda  $name+1 |  eor  #>$value |  sta  $name+1")
-                    value < 0x0100 -> asmgen.out("  lda  $name |  eor  #$value |  sta  $name")
-                    else -> asmgen.out("  lda  $name |  eor  #<$value |  sta  $name |  lda  $name+1 |  eor  #>$value |  sta  $name+1")
-                }
-            }
-            "|" -> {
+            "|", "or" -> {
                 when {
                     value == 0 -> {}
                     value and 255 == 0 -> asmgen.out("  lda  $name+1 |  ora  #>$value |  sta  $name+1")
@@ -990,6 +971,15 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                     else -> asmgen.out("  lda  $name |  ora  #<$value |  sta  $name |  lda  $name+1 |  ora  #>$value |  sta  $name+1")
                 }
             }
+            "^", "xor" -> {
+                when {
+                    value == 0 -> {}
+                    value and 255 == 0 -> asmgen.out("  lda  $name+1 |  eor  #>$value |  sta  $name+1")
+                    value < 0x0100 -> asmgen.out("  lda  $name |  eor  #$value |  sta  $name")
+                    else -> asmgen.out("  lda  $name |  eor  #<$value |  sta  $name |  lda  $name+1 |  eor  #>$value |  sta  $name+1")
+                }
+            }
+            in comparisonOperators -> TODO("in-place modification for $operator")
             else -> throw AssemblyError("invalid operator for in-place modification $operator")
         }
     }
@@ -1100,7 +1090,7 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
 +""")
                         }
                     }
-                    "&" -> {
+                    "&", "and" -> {
                         asmgen.out("  lda  $otherName |  and  $name |  sta  $name")
                         if(dt in WordDatatypes) {
                             if(CompilationTarget.instance.machine.cpu == CpuType.CPU65c02)
@@ -1109,8 +1099,9 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                                 asmgen.out("  lda  #0 |  sta  $name+1")
                         }
                     }
-                    "^" -> asmgen.out("  lda  $otherName |  eor  $name |  sta  $name")
-                    "|" -> asmgen.out("  lda  $otherName |  ora  $name |  sta  $name")
+                    "|", "or" -> asmgen.out("  lda  $otherName |  ora  $name |  sta  $name")
+                    "^", "xor" -> asmgen.out("  lda  $otherName |  eor  $name |  sta  $name")
+                    in comparisonOperators -> TODO("in-place modification for $operator")
                     else -> throw AssemblyError("invalid operator for in-place modification $operator")
                 }
             }
@@ -1181,9 +1172,10 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                         """)
                     }
                     "<<", ">>" -> throw AssemblyError("shift by a word value not supported, max is a byte")
-                    "&" -> asmgen.out(" lda  $name |  and  $otherName |  sta  $name |  lda  $name+1 |  and  $otherName+1 |  sta  $name+1")
-                    "^" -> asmgen.out(" lda  $name |  eor  $otherName |  sta  $name |  lda  $name+1 |  eor  $otherName+1 |  sta  $name+1")
-                    "|" -> asmgen.out(" lda  $name |  ora  $otherName |  sta  $name |  lda  $name+1 |  ora  $otherName+1 |  sta  $name+1")
+                    "&", "and" -> asmgen.out(" lda  $name |  and  $otherName |  sta  $name |  lda  $name+1 |  and  $otherName+1 |  sta  $name+1")
+                    "|", "or" -> asmgen.out(" lda  $name |  ora  $otherName |  sta  $name |  lda  $name+1 |  ora  $otherName+1 |  sta  $name+1")
+                    "^", "xor" -> asmgen.out(" lda  $name |  eor  $otherName |  sta  $name |  lda  $name+1 |  eor  $otherName+1 |  sta  $name+1")
+                    in comparisonOperators -> TODO("in-place modification for $operator")
                     else -> throw AssemblyError("invalid operator for in-place modification $operator")
                 }
             }
@@ -1356,7 +1348,7 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                             bne  -
 +""")
                     }
-                    "&" -> {
+                    "&", "and" -> {
                         asmgen.assignExpressionToRegister(value, RegisterOrPair.A)
                         asmgen.out("  and  $name |  sta  $name")
                         if(dt in WordDatatypes) {
@@ -1366,14 +1358,15 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                                 asmgen.out("  lda  #0 |  sta  $name+1")
                         }
                     }
-                    "^" -> {
-                        asmgen.assignExpressionToRegister(value, RegisterOrPair.A)
-                        asmgen.out("  eor  $name |  sta  $name")
-                    }
-                    "|" -> {
+                    "|", "or" -> {
                         asmgen.assignExpressionToRegister(value, RegisterOrPair.A)
                         asmgen.out("  ora  $name |  sta  $name")
                     }
+                    "^", "xor" -> {
+                        asmgen.assignExpressionToRegister(value, RegisterOrPair.A)
+                        asmgen.out("  eor  $name |  sta  $name")
+                    }
+                    in comparisonOperators -> TODO("in-place modification for $operator")
                     else -> throw AssemblyError("invalid operator for in-place modification $operator")
                 }
             }
@@ -1402,18 +1395,19 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                         remainderVarByWordInAY()
                     }
                     "<<", ">>" -> throw AssemblyError("shift by a word value not supported, max is a byte")
-                    "&" -> {
+                    "&", "and" -> {
                         asmgen.assignExpressionToRegister(value, RegisterOrPair.AY)
                         asmgen.out("  and  $name |  sta  $name |  tya |  and  $name+1 |  sta  $name+1")
                     }
-                    "^" -> {
-                        asmgen.assignExpressionToRegister(value, RegisterOrPair.AY)
-                        asmgen.out("  eor  $name |  sta  $name |  tya |  eor  $name+1 |  sta  $name+1")
-                    }
-                    "|" -> {
+                    "|", "or" -> {
                         asmgen.assignExpressionToRegister(value, RegisterOrPair.AY)
                         asmgen.out("  ora  $name |  sta  $name |  tya |  ora  $name+1 |  sta  $name+1")
                     }
+                    "^", "xor" -> {
+                        asmgen.assignExpressionToRegister(value, RegisterOrPair.AY)
+                        asmgen.out("  eor  $name |  sta  $name |  tya |  eor  $name+1 |  sta  $name+1")
+                    }
+                    in comparisonOperators -> TODO("in-place modification for $operator")
                     else -> throw AssemblyError("invalid operator for in-place modification $operator")
                 }
             }
@@ -1461,6 +1455,7 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                     jsr  floats.FDIV
                 """)
             }
+            in comparisonOperators -> TODO("in-place float modification for $operator")
             else -> throw AssemblyError("invalid operator for in-place float modification $operator")
         }
         asmgen.out("""
@@ -1480,14 +1475,26 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
         asmgen.saveRegister(CpuRegister.X, false, scope)
         when (operator) {
             "**" -> {
-                asmgen.out("""
-                    lda  #<$name
-                    ldy  #>$name
-                    jsr  floats.CONUPK
-                    lda  #<$otherName
-                    ldy  #>$otherName
-                    jsr  floats.FPWR
-                """)
+                if(CompilationTarget.instance is Cx16Target) {
+                    // cx16 doesn't have FPWR() only FPWRT()
+                    asmgen.out("""
+                        lda  #<$name
+                        ldy  #>$name
+                        jsr  floats.CONUPK
+                        lda  #<$otherName
+                        ldy  #>$otherName
+                        jsr  floats.MOVFM
+                        jsr  floats.FPWRT
+                    """)
+                } else
+                    asmgen.out("""
+                        lda  #<$name
+                        ldy  #>$name
+                        jsr  floats.CONUPK
+                        lda  #<$otherName
+                        ldy  #>$otherName
+                        jsr  floats.FPWR
+                    """)
             }
             "+" -> {
                 asmgen.out("""
@@ -1529,6 +1536,7 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                     jsr  floats.FDIV
                 """)
             }
+            in comparisonOperators -> TODO("in-place float modification for $operator")
             else -> throw AssemblyError("invalid operator for in-place float modification $operator")
         }
         // store Fac1 back into memory
@@ -1545,14 +1553,26 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
         asmgen.saveRegister(CpuRegister.X, false, scope)
         when (operator) {
             "**" -> {
-                asmgen.out("""
-                    lda  #<$name
-                    ldy  #>$name
-                    jsr  floats.CONUPK
-                    lda  #<$constValueName
-                    ldy  #>$constValueName
-                    jsr  floats.FPWR
-                """)
+                if(CompilationTarget.instance is Cx16Target) {
+                    // cx16 doesn't have FPWR() only FPWRT()
+                    asmgen.out("""
+                        lda  #<$name
+                        ldy  #>$name
+                        jsr  floats.CONUPK
+                        lda  #<$constValueName
+                        ldy  #>$constValueName
+                        jsr  floats.MOVFM
+                        jsr  floats.FPWRT
+                    """)
+                } else
+                    asmgen.out("""
+                        lda  #<$name
+                        ldy  #>$name
+                        jsr  floats.CONUPK
+                        lda  #<$constValueName
+                        ldy  #>$constValueName
+                        jsr  floats.FPWR
+                    """)
             }
             "+" -> {
                 if (value == 0.0)
@@ -1601,6 +1621,7 @@ internal class AugmentableAssignmentAsmGen(private val program: Program,
                     jsr  floats.FDIV
                 """)
             }
+            in comparisonOperators -> TODO("in-place float modification for $operator")
             else -> throw AssemblyError("invalid operator for in-place float modification $operator")
         }
         // store Fac1 back into memory

compiler/src/prog8/compiler/target/cx16/CX16MachineDefinition.kt

@@ -38,8 +38,7 @@ internal object CX16MachineDefinition: IMachineDefinition {
     override fun launchEmulator(programName: String) {
         for(emulator in listOf("x16emu")) {
             println("\nStarting Commander X16 emulator $emulator...")
-            val cmdline = listOf(emulator, "-rom", "/usr/share/x16-rom/rom.bin", "-scale", "2",
-                    "-run", "-prg", programName + ".prg")
+            val cmdline = listOf(emulator, "-scale", "2", "-run", "-prg", "$programName.prg")
             val processb = ProcessBuilder(cmdline).inheritIO()
             val process: Process
             try {

compiler/src/prog8/functions/BuiltinFunctions.kt

@@ -141,6 +141,7 @@ private val functionSignatures: List<FSignature> = listOf(
     FSignature("set_irqd"    , false, emptyList(), null),
     FSignature("clear_irqd"  , false, emptyList(), null),
     FSignature("read_flags"  , false, emptyList(), DataType.UBYTE),
+    FSignature("progend"     , true, emptyList(), DataType.UWORD),
     FSignature("swap"        , false, listOf(FParam("first", NumericDatatypes), FParam("second", NumericDatatypes)), null),
     FSignature("memcopy"     , false, listOf(
                             FParam("from", IterableDatatypes + DataType.UWORD),
@@ -155,6 +156,7 @@ private val functionSignatures: List<FSignature> = listOf(
                             FParam("numwords", setOf(DataType.UWORD)),
                             FParam("wordvalue", setOf(DataType.UWORD, DataType.WORD))), null),
     FSignature("strlen"      , true, listOf(FParam("string", setOf(DataType.STR))), DataType.UBYTE, ::builtinStrlen),
+    FSignature("strcopy"     , false, listOf(FParam("from", IterableDatatypes + DataType.UWORD), FParam("to", IterableDatatypes + DataType.UWORD)), DataType.UBYTE),
     FSignature("substr"      , false, listOf(
             FParam("source", IterableDatatypes + DataType.UWORD),
             FParam("target", IterableDatatypes + DataType.UWORD),
@@ -353,7 +355,7 @@ private fun builtinStrlen(args: List<Expression>, position: Position, program: P
     val argument=args[0]
     if(argument is StringLiteralValue)
         return NumericLiteralValue.optimalInteger(argument.value.length, argument.position)
-    val vardecl = (argument as IdentifierReference).targetVarDecl(program.namespace)
+    val vardecl = (argument as? IdentifierReference)?.targetVarDecl(program.namespace)
     if(vardecl!=null) {
         if(vardecl.datatype!=DataType.STR && vardecl.datatype!=DataType.UWORD)
             throw SyntaxError("strlen must have string argument", position)

compiler/src/prog8/optimizer/ConstantFoldingOptimizer.kt

@@ -7,6 +7,7 @@ import prog8.ast.expressions.*
 import prog8.ast.processing.AstWalker
 import prog8.ast.processing.IAstModification
 import prog8.ast.statements.*
+import kotlin.math.pow
 
 
 internal class ConstantFoldingOptimizer(private val program: Program) : AstWalker() {
@@ -97,6 +98,43 @@ internal class ConstantFoldingOptimizer(private val program: Program) : AstWalke
     override fun after(expr: BinaryExpression, parent: Node): Iterable<IAstModification> {
         val leftconst = expr.left.constValue(program)
         val rightconst = expr.right.constValue(program)
+        val modifications = mutableListOf<IAstModification>()
+
+        if(expr.operator == "**" && leftconst!=null) {
+            // optimize various simple cases of ** :
+            //  optimize away 1 ** x into just 1 and 0 ** x into just 0
+            //  optimize 2 ** x into (1<<x)  if both operands are integer.
+            val leftDt = leftconst.inferType(program).typeOrElse(DataType.STRUCT)
+            when (leftconst.number.toDouble()) {
+                0.0 -> {
+                    val value = NumericLiteralValue(leftDt, 0, expr.position)
+                    modifications += IAstModification.ReplaceNode(expr, value, parent)
+                }
+                1.0 -> {
+                    val value = NumericLiteralValue(leftDt, 1, expr.position)
+                    modifications += IAstModification.ReplaceNode(expr, value, parent)
+                }
+                2.0 -> {
+                    if(rightconst!=null) {
+                        val value = NumericLiteralValue(leftDt, 2.0.pow(rightconst.number.toDouble()), expr.position)
+                        modifications += IAstModification.ReplaceNode(expr, value, parent)
+                    } else {
+                        val rightDt = expr.right.inferType(program).typeOrElse(DataType.STRUCT)
+                        if(leftDt in IntegerDatatypes && rightDt in IntegerDatatypes) {
+                            val targetDt =
+                                when (parent) {
+                                    is Assignment -> parent.target.inferType(program).typeOrElse(DataType.STRUCT)
+                                    is VarDecl -> parent.datatype
+                                    else -> leftDt
+                                }
+                            val one = NumericLiteralValue(targetDt, 1, expr.position)
+                            val shift = BinaryExpression(one, "<<", expr.right, expr.position)
+                            modifications += IAstModification.ReplaceNode(expr, shift, parent)
+                        }
+                    }
+                }
+            }
+        }
 
         val subExpr: BinaryExpression? = when {
             leftconst!=null -> expr.right as? BinaryExpression
@@ -111,7 +149,8 @@ internal class ConstantFoldingOptimizer(private val program: Program) : AstWalke
                 val change = groupTwoConstsTogether(expr, subExpr,
                         leftconst != null, rightconst != null,
                         subleftconst != null, subrightconst != null)
-                return change?.let { listOf(it) } ?: noModifications
+                if(change!=null)
+                    modifications += change
             }
         }
 
@@ -119,10 +158,10 @@ internal class ConstantFoldingOptimizer(private val program: Program) : AstWalke
         if(leftconst != null && rightconst != null) {
             val evaluator = ConstExprEvaluator()
             val result = evaluator.evaluate(leftconst, expr.operator, rightconst)
-            return listOf(IAstModification.ReplaceNode(expr, result, parent))
+            modifications += IAstModification.ReplaceNode(expr, result, parent)
         }
 
-        return noModifications
+        return modifications
     }
 
     override fun after(array: ArrayLiteralValue, parent: Node): Iterable<IAstModification> {

compiler/src/prog8/optimizer/ExpressionSimplifier.kt

@@ -6,6 +6,7 @@ import prog8.ast.base.*
 import prog8.ast.expressions.*
 import prog8.ast.processing.AstWalker
 import prog8.ast.processing.IAstModification
+import prog8.ast.statements.Assignment
 import kotlin.math.abs
 import kotlin.math.log2
 import kotlin.math.pow
@@ -98,6 +99,12 @@ internal class ExpressionSimplifier(private val program: Program) : AstWalker()
         if (leftVal != null && expr.operator in associativeOperators && rightVal == null)
             return listOf(IAstModification.SwapOperands(expr))
 
+        // NonBinaryExpression  <associativeoperator>  BinaryExpression  -->  BinaryExpression  <associativeoperator>  NonBinaryExpression
+        if (expr.operator in associativeOperators && expr.left !is BinaryExpression && expr.right is BinaryExpression) {
+            if(parent !is Assignment || !(expr.left isSameAs parent.target))
+                return listOf(IAstModification.SwapOperands(expr))
+        }
+
         // X + (-A)  -->  X - A
         if (expr.operator == "+" && (expr.right as? PrefixExpression)?.operator == "-") {
             return listOf(IAstModification.ReplaceNode(
@@ -338,7 +345,7 @@ internal class ExpressionSimplifier(private val program: Program) : AstWalker()
         if (leftVal == null && rightVal == null)
             return null
 
-        val (expr2, _, rightVal2) = reorderAssociative(expr, leftVal)
+        val (expr2, _, rightVal2) = reorderAssociativeWithConstant(expr, leftVal)
         if (rightVal2 != null) {
             // right value is a constant, see if we can optimize
             val rightConst: NumericLiteralValue = rightVal2
@@ -562,7 +569,7 @@ internal class ExpressionSimplifier(private val program: Program) : AstWalker()
         if (leftVal == null && rightVal == null)
             return null
 
-        val (expr2, _, rightVal2) = reorderAssociative(expr, leftVal)
+        val (expr2, _, rightVal2) = reorderAssociativeWithConstant(expr, leftVal)
         if (rightVal2 != null) {
             // right value is a constant, see if we can optimize
             val leftValue: Expression = expr2.left
@@ -682,17 +689,17 @@ internal class ExpressionSimplifier(private val program: Program) : AstWalker()
         return null
     }
 
-    private fun reorderAssociative(expr: BinaryExpression, leftVal: NumericLiteralValue?): ReorderedAssociativeBinaryExpr {
+    private fun reorderAssociativeWithConstant(expr: BinaryExpression, leftVal: NumericLiteralValue?): BinExprWithConstants {
         if (expr.operator in associativeOperators && leftVal != null) {
             // swap left and right so that right is always the constant
             val tmp = expr.left
             expr.left = expr.right
             expr.right = tmp
-            return ReorderedAssociativeBinaryExpr(expr, expr.right.constValue(program), leftVal)
+            return BinExprWithConstants(expr, expr.right.constValue(program), leftVal)
         }
-        return ReorderedAssociativeBinaryExpr(expr, leftVal, expr.right.constValue(program))
+        return BinExprWithConstants(expr, leftVal, expr.right.constValue(program))
     }
 
-    private data class ReorderedAssociativeBinaryExpr(val expr: BinaryExpression, val leftVal: NumericLiteralValue?, val rightVal: NumericLiteralValue?)
+    private data class BinExprWithConstants(val expr: BinaryExpression, val leftVal: NumericLiteralValue?, val rightVal: NumericLiteralValue?)
 
 }

compiler/src/prog8/optimizer/StatementOptimizer.kt

@@ -323,7 +323,7 @@ internal class StatementOptimizer(private val program: Program,
                     val op1 = binExpr.operator
                     val op2 = rExpr.operator
 
-                    if(rExpr.left is NumericLiteralValue && op2 in setOf("+", "*", "&", "|")) {
+                    if(rExpr.left is NumericLiteralValue && op2 in associativeOperators) {
                         // associative operator, make sure the constant numeric value is second (right)
                         return listOf(IAstModification.SwapOperands(rExpr))
                     }

compiler/src/prog8/parser/ModuleParsing.kt

@@ -102,7 +102,7 @@ internal class ModuleImporter {
 
     private fun discoverImportedModuleFile(name: String, source: Path, position: Position?): Path {
         val fileName = "$name.p8"
-        val locations = if(source.toString().isEmpty()) mutableListOf<Path>() else mutableListOf(source.parent)
+        val locations = if(source.toString().isEmpty()) mutableListOf<Path>() else mutableListOf(source.parent ?: Path.of("."))
 
         val propPath = System.getProperty("prog8.libdir")
         if(propPath!=null)

docs/source/programming.rst

@@ -814,6 +814,12 @@ substr(source, target, start, length)
     Also, you have to make sure yourself that start and length are within bounds of the strings.
     Modifies in-place, doesn't return a value (so can't be used in an expression).
 
+strcopy(from, to)
+    Copy a string to another, overwriting that one. Returns the length of the string that was copied.
+    Often you don't have to call this explicitly and can just write ``string1 = string2``
+    but this function is useful if you're dealing with addresses for instance.
+
+
 Miscellaneous
 ^^^^^^^^^^^^^
 exit(returncode)
@@ -830,6 +836,12 @@ mkword(msb, lsb)
     Efficiently create a word value from two bytes (the msb and the lsb). Avoids multiplication and shifting.
     So mkword($80, $22) results in $8022.
 
+    .. note::
+        The arguments to the mkword() function are in 'natural' order that is first the msb then the lsb.
+        Don't get confused by how the system actually stores this 16-bit word value in memory (which is
+        in little-endian format, so lsb first then msb)
+
+
 rnd()
     returns a pseudo-random byte from 0..255
 
@@ -894,6 +906,10 @@ set_irqd()  /  clear_irqd()
 swap(x, y)
     Swap the values of numerical variables (or memory locations) x and y in a fast way.
 
+progend()
+    Returns the last address of the program in memory + 1.
+    Can be used to load dynamic data after the program, instead of hardcoding something.
+
 
 Library routines
 ----------------

examples/arithmetic/builtins.p8

@@ -324,6 +324,10 @@ main {
         txt.print(result)
         txt.chrout('\n')
 
+        void strcopy(s2, s1)
+        txt.print_ub(99+strcopy(s2,s1))
+        txt.chrout('\n')
+
         test_stack.test()
 
     }

examples/balloonflight.p8

@@ -4,6 +4,12 @@
 %import test_stack
 %zeropage basicsafe
 
+; note: The flickering in the scrolling is caused by the CPU requiring
+;       too long to scroll the characters + the colors in course scroll.
+;       This takes nearly a full frame to accomplish, and causes tearing.
+;       It's very difficult to remove this flicker: it requires double buffering
+;       and splitting the coarse character scrolling on multiple phases...
+
 main {
 
     ubyte perform_scroll = false
@@ -17,7 +23,7 @@ main {
 
         c64.SCROLX &= %11110111     ; 38 column mode
 
-        c64.set_rasterirq(40)     ; enable animation
+        c64.set_rasterirq(200)     ; enable animation
 
         ubyte target_height = 10
         ubyte active_height = 24
@@ -123,10 +129,10 @@ spritedata $0f00 {
 
 
 irq {
-    ubyte smoothx=7
+    ubyte smoothx=0
     sub irq() {
         smoothx = (smoothx-1) & 7
-        main.perform_scroll = smoothx==0
+        main.perform_scroll = smoothx==7
         c64.SCROLX = (c64.SCROLX & %11111000) | smoothx
     }
 }

examples/cx16/imageviewer/bmp_module.p8

@@ -0,0 +1,125 @@
+%target cx16
+%import graphics
+%import diskio
+
+bmp_module {
+
+    sub show_image(uword filenameptr) -> ubyte {
+        ubyte load_ok = false
+        ubyte[$36] header
+        uword size
+        uword width
+        uword height
+        ubyte bpp
+        uword offsetx
+        uword offsety
+        ubyte[256] palette0
+        ubyte[256] palette1
+        ubyte[256] palette2
+        ubyte[256] palette3
+        uword total_read = 0
+
+        palette0[0] = 0
+        palette1[0] = 0
+        palette2[0] = 0
+        palette3[0] = 0
+
+        if diskio.f_open(8, filenameptr) {
+            size = diskio.f_read(header, $36)
+            if size==$36 {
+                total_read = $36
+                if header[0]=='b' and header[1]=='m' {
+                    uword bm_data_offset = mkword(header[11], header[10])
+                    uword header_size = mkword(header[$f], header[$e])
+                    width = mkword(header[$13], header[$12])
+                    height = mkword(header[$17], header[$16])
+                    bpp = header[$1c]
+                    uword num_colors = header[$2e]
+                    if num_colors == 0
+                        num_colors = 2**bpp
+                    uword skip_hdr = header_size - 40
+                    repeat skip_hdr
+                        void c64.CHRIN()
+                    total_read += skip_hdr
+                    size = diskio.f_read(&palette0, num_colors*4)
+                    if size==num_colors*4 {
+                        total_read += size
+                        repeat bm_data_offset - total_read
+                            void c64.CHRIN()
+                        graphics.clear_screen(1, 0)
+                        palette.set_bgra(&palette0, num_colors)
+                        decode_bitmap()
+                        load_ok = true
+                    }
+                }
+            }
+
+            diskio.f_close()
+        }
+
+        return load_ok
+
+        sub start_plot() {
+            offsetx = 0
+            offsety = 0
+            if width < graphics.WIDTH
+                offsetx = (graphics.WIDTH - width - 1) / 2
+            if height < graphics.HEIGHT
+                offsety = (graphics.HEIGHT - height - 1) / 2
+            if width > graphics.WIDTH
+                width = graphics.WIDTH
+            if height > graphics.HEIGHT-1
+                height = graphics.HEIGHT-1
+        }
+
+        sub set_cursor(uword x, uword y) {
+            cx16.r0=offsetx+x
+            cx16.r1=offsety+y
+            cx16.FB_cursor_position()
+        }
+
+        sub decode_bitmap() {
+            start_plot()
+            uword bits_width = width * bpp
+            ubyte pad_bytes = (((bits_width + 31) >> 5) << 2) - ((bits_width + 7) >> 3) as ubyte
+
+            uword x
+            uword y
+            ubyte b
+            for y in height-1 downto 0 {
+                set_cursor(0, y)
+                when bpp {
+                    8 -> {
+                        for x in 0 to width-1
+                            cx16.FB_set_pixel(c64.CHRIN())
+                    }
+                    4 -> {
+                        for x in 0 to width-1 step 2 {
+                            b = c64.CHRIN()
+                            cx16.FB_set_pixel(b>>4)
+                            cx16.FB_set_pixel(b&15)
+                        }
+                    }
+                    2 -> {
+                        for x in 0 to width-1 step 4 {
+                            b = c64.CHRIN()
+                            cx16.FB_set_pixel(b>>6)
+                            cx16.FB_set_pixel(b>>4 & 3)
+                            cx16.FB_set_pixel(b>>2 & 3)
+                            cx16.FB_set_pixel(b & 3)
+                        }
+                    }
+                    1 -> {
+                        for x in 0 to width-1 step 8 {
+                            cx16.r0 = c64.CHRIN()
+                            cx16.FB_set_8_pixels_opaque(255, 255, 0)
+                        }
+                    }
+                }
+
+                repeat pad_bytes
+                    void c64.CHRIN()
+            }
+        }
+    }
+}

examples/cx16/imageviewer/ci_module.p8

@@ -0,0 +1,140 @@
+%target cx16
+%import graphics
+%import textio
+%import diskio
+%option no_sysinit
+
+; CommanderX16 Image file format.  (EXPERIMENTAL/ UNFINISHED)
+; Numbers are encoded in little endian format (lsb first).
+;
+; offset      value
+; -----------------
+; HEADER (12 bytes):
+; 0-1    'CI' in petscii , from "CommanderX16 Image".
+; 2      Size of the header data following this byte (always 9, could become more if format changes)
+; 3-4    Width in pixels  (must be multiple of 8)
+; 5-6    Height in pixels
+; 7      Bits-per-pixel  (1, 2, 4 or 8)  (= 2, 4, 16 or 256 colors)
+;          this also determines the number of palette entries following later.
+; 8      Settings bits.
+;          bit 0 and 1 = compression.  00 = uncompressed
+;                                      01 = RLE        [TODO not yet implemented]
+;                                      10 = LZSA       [TODO not yet implemented]
+;                                      11 = Exomizer   [TODO not yet implemented]
+;          bit 2 = palette format.  0 = 4 bits/channel  (2 bytes per color, $0R $GB)
+;                                   1 = 8 bits/channel  (3 bytes per color, $RR $GG $BB)
+;                  4 bits per channel is what the Vera in the Cx16 supports.
+;          bit 3 = bitmap format.   0 = raw bitmap pixels
+;                                   1 = tile-based image   [TODO not yet implemented]
+;          bit 4 = hscale (horizontal display resulution) 0 = 320 pixels, 1 = 640 pixels
+;          bit 5 = vscale (vertical display resulution) 0 = 240 pixels, 1 = 480 pixels
+;          bit 6,7: reserved, set to 0
+; 9-11   Size of the bitmap data following the palette data.
+;          This is a 24-bits number, can be 0 ("unknown", in which case just read until the end).
+;
+; PALETTE (always present but size varies):
+; 12-... Color palette. Number of entries = 2 ^ bits-per-pixel.  Number of bytes per
+;          entry is 2 or 3, depending on the chosen palette format in the setting bits.
+;
+; BITMAPDATA (size varies):
+; After this, the actual image data follows.
+; If the bitmap format is 'raw bitmap pixels', the bimap is simply written as a sequence
+; of bytes making up the image's scan lines. #bytes per scan line = width * bits-per-pixel / 8
+; If it is 'tiles', .... [TODO]
+; If a compression scheme is used, the bitmap data here has to be decompressed first.
+; TODO: with compressed files, store the data in compressed chunks of max 8kb uncompressed?
+; (it is a problem to load let alone decompress a full bitmap at once because there will likely not be enough ram to do that)
+; (doing it in chunks of 8 kb allows for sticking each chunk in one of the banked 8kb ram blocks, or even copy it directly to the screen)
+
+ci_module {
+    %option force_output
+    ubyte[256] buffer
+    ubyte[256] buffer2  ; add two more buffers to make enough space
+    ubyte[256] buffer3  ;   to store a 256 color palette
+    ubyte[256] buffer4  ;  .. and some more to be able to store 1280=
+    ubyte[256] buffer5  ;     two 640 bytes worth of bitmap scanline data
+
+    sub show_image(uword filename) -> ubyte {
+        ubyte read_success = false
+        uword bitmap_load_address = progend()
+        ; uword max_bitmap_size = $9eff - bitmap_load_address
+
+        if(diskio.f_open(8, filename)) {
+            uword size = diskio.f_read(buffer, 12)  ; read the header
+            if size==12 {
+                if buffer[0]=='c' and buffer[1]=='i' and buffer[2] == 9 {
+                    uword width = mkword(buffer[4], buffer[3])
+                    uword height = mkword(buffer[6], buffer[5])
+                    ubyte bpp = buffer[7]
+                    uword num_colors = 2 ** bpp
+                    ubyte flags = buffer[8]
+                    ubyte compression = flags & %00000011
+                    ubyte palette_format = (flags & %00000100) >> 2
+                    ubyte bitmap_format = (flags & %00001000) >> 3
+                    ; ubyte hscale = (flags & %00010000) >> 4
+                    ; ubyte vscale = (flags & %00100000) >> 5
+                    uword bitmap_size = mkword(buffer[10], buffer[9])
+                    uword palette_size = num_colors*2
+                    if palette_format
+                        palette_size += num_colors  ; 3
+                    if width > graphics.WIDTH {
+                        txt.print("image is too wide for the display!\n")
+                    } else if compression!=0 {
+                        txt.print("compressed image not yet supported!\n")    ; TODO implement the various decompressions
+                    } else if bitmap_format==1 {
+                        txt.print("tiled bitmap not yet supported!\n")       ; TODO implement tiled image
+                    } else {
+                        size = diskio.f_read(buffer, palette_size)
+                        if size==palette_size {
+                            if compression {
+                                txt.print("todo: compressed image support\n")
+                            } else {
+                                ; uncompressed bitmap data. read it a scanline at a time and display as we go.
+                                ; restrict height to the maximun that can be displayed
+                                if height > graphics.HEIGHT
+                                    height = graphics.HEIGHT
+                                graphics.enable_bitmap_mode()
+                                if palette_format
+                                    palette.set_rgb8(buffer, num_colors)
+                                else
+                                    palette.set_rgb4(buffer, num_colors)
+                                graphics.clear_screen(1,0)
+                                cx16.r0 = 0
+                                cx16.r1 = 0
+                                cx16.FB_cursor_position()
+                                uword scanline_size = width * bpp / 8
+                                ubyte y
+                                for y in 0 to lsb(height)-1 {
+                                    void diskio.f_read(buffer, scanline_size)
+                                    when bpp {
+                                        8 -> cx16.FB_set_pixels_from_buf(buffer, scanline_size)  ; FB_set_pixels in rom v38 crashes with a size > 255 so we use our own replacement for now
+                                        4 -> display_scanline_16c(buffer, scanline_size)
+                                        2 -> display_scanline_4c(buffer, scanline_size)
+                                        1 -> display_scanline_2c(buffer, scanline_size)
+                                    }
+                                }
+                                read_success = true
+                            }
+                        }
+                    }
+                }
+            }
+
+            diskio.f_close()
+        }
+
+        return read_success
+    }
+
+    sub display_scanline_16c(uword dataptr, uword numbytes) {
+        ; TODO
+    }
+
+    sub display_scanline_4c(uword dataptr, uword numbytes) {
+        ; TODO
+    }
+
+    sub display_scanline_2c(uword dataptr, uword numbytes) {
+        ; TODO
+    }
+}

examples/cx16/imageviewer/iff_module.p8

@@ -0,0 +1,214 @@
+%target cx16
+%import graphics
+%import textio
+%import diskio
+
+iff_module {
+    sub show_image(uword filenameptr) -> ubyte {
+        ubyte load_ok = false
+        uword size
+        ubyte[32] buffer
+        ubyte[256] cmap
+        ubyte[256] cmap1
+        ubyte[256] cmap2
+        uword camg = 0
+        str chunk_id = "????"
+        uword chunk_size_hi
+        uword chunk_size_lo
+        uword scanline_data_ptr = progend()
+
+        uword width
+        uword height
+        ubyte num_planes
+        uword num_colors
+        ubyte compression
+        ubyte have_cmap = false
+        cmap[0] = 0
+        cmap1[0] = 0
+        cmap2[0] = 0
+
+        if diskio.f_open(8, filenameptr) {
+            size = diskio.f_read(buffer, 12)
+            if size==12 {
+                if buffer[0]=='f' and buffer[1]=='o' and buffer[2]=='r' and buffer[3]=='m'
+                        and buffer[8]=='i' and buffer[9]=='l' and buffer[10]=='b' and buffer[11]=='m'{
+
+                    while read_chunk_header() {
+                        if chunk_id == "bmhd" {
+                            void diskio.f_read(buffer, chunk_size_lo)
+                            width = mkword(buffer[0], buffer[1])
+                            height = mkword(buffer[2], buffer[3])
+                            num_planes = buffer[8]
+                            num_colors = 2 ** num_planes
+                            compression = buffer[10]
+                        }
+                        else if chunk_id == "camg" {
+                            void diskio.f_read(buffer, chunk_size_lo)
+                            camg = mkword(buffer[2], buffer[3])
+                            if camg & $0800 {
+                                txt.print("ham mode not supported!\n")
+                                break
+                            }
+                        }
+                        else if chunk_id == "cmap" {
+                            have_cmap = true
+                            void diskio.f_read(&cmap, chunk_size_lo)
+                        }
+                        else if chunk_id == "body" {
+                            graphics.clear_screen(1, 0)
+                            if camg & $0004
+                                height /= 2     ; interlaced: just skip every odd scanline later
+                            if camg & $0080 and have_cmap
+                                make_ehb_palette()
+                            palette.set_rgb8(&cmap, num_colors)
+                            if compression
+                                decode_rle()
+                            else
+                                decode_raw()
+                            load_ok = true
+                            break   ; done after body
+                        }
+                        else {
+                            skip_chunk()
+                        }
+                    }
+                } else
+                    txt.print("not an iff ilbm file!\n")
+            }
+
+            diskio.f_close()
+        }
+
+        return load_ok
+
+        sub read_chunk_header() -> ubyte {
+            size = diskio.f_read(buffer, 8)
+            if size==8 {
+                chunk_id[0] = buffer[0]
+                chunk_id[1] = buffer[1]
+                chunk_id[2] = buffer[2]
+                chunk_id[3] = buffer[3]
+                chunk_size_hi = mkword(buffer[4], buffer[5])
+                chunk_size_lo = mkword(buffer[6], buffer[7])
+                return true
+            }
+            return false
+        }
+
+        sub skip_chunk() {
+            repeat lsb(chunk_size_hi)*8 + (chunk_size_lo >> 13)
+                void diskio.f_read(scanline_data_ptr, $2000)
+
+            void diskio.f_read(scanline_data_ptr, chunk_size_lo & $1fff)
+        }
+
+        sub make_ehb_palette() {
+            ; generate 32 additional Extra-Halfbrite colors in the cmap
+            uword palletteptr = &cmap
+            uword ehbptr = palletteptr + 32*3
+            repeat 32 {
+                @(ehbptr) = @(palletteptr)>>1
+                ehbptr++
+                palletteptr++
+                @(ehbptr) = @(palletteptr)>>1
+                ehbptr++
+                palletteptr++
+                @(ehbptr) = @(palletteptr)>>1
+                ehbptr++
+                palletteptr++
+            }
+        }
+
+        uword bitplane_stride
+        uword interleave_stride
+        uword offsetx
+        uword offsety
+
+        sub start_plot() {
+            bitplane_stride = width>>3
+            interleave_stride = bitplane_stride * num_planes
+            offsetx = 0
+            offsety = 0
+            if width < graphics.WIDTH
+                offsetx = (graphics.WIDTH - width - 1) / 2
+            if height < graphics.HEIGHT
+                offsety = (graphics.HEIGHT - height - 1) / 2
+            if width > graphics.WIDTH
+                width = graphics.WIDTH
+            if height > graphics.HEIGHT-1
+                height = graphics.HEIGHT-1
+        }
+
+        sub set_cursor(uword x, uword y) {
+            cx16.r0=offsetx+x
+            cx16.r1=offsety+y
+            cx16.FB_cursor_position()
+        }
+
+        sub decode_raw() {
+            start_plot()
+            ubyte interlaced = (camg & $0004) != 0
+            uword y
+            for y in 0 to height-1 {
+                void diskio.f_read(scanline_data_ptr, interleave_stride)
+                if interlaced
+                    void diskio.f_read(scanline_data_ptr, interleave_stride)
+                set_cursor(0, y)
+                planar_to_chunky_scanline()
+            }
+        }
+
+        sub decode_rle() {
+            start_plot()
+            ubyte interlaced = (camg & $0004) != 0
+            uword y
+            for y in 0 to height-1 {
+                decode_rle_scanline()
+                if interlaced
+                    decode_rle_scanline()
+                set_cursor(0, y)
+                planar_to_chunky_scanline()
+            }
+        }
+
+        sub decode_rle_scanline() {
+            uword x = interleave_stride
+            uword plane_ptr = scanline_data_ptr
+
+            while x {
+                ubyte b = c64.CHRIN()
+                if b > 128 {
+                    ubyte b2 = c64.CHRIN()
+                    repeat 2+(b^255) {
+                        @(plane_ptr) = b2
+                        plane_ptr++
+                        x--
+                    }
+                } else if b < 128 {
+                    repeat b+1 {
+                        @(plane_ptr) = c64.CHRIN()
+                        plane_ptr++
+                        x--
+                    }
+                } else
+                    break
+            }
+        }
+
+        sub planar_to_chunky_scanline() {
+            uword x
+            for x in 0 to width-1 {
+                ubyte bitnr = ((lsb(x) ^ 255) & 7) + 1
+                uword pixptr = x/8 + scanline_data_ptr
+                ubyte bits=0
+                repeat num_planes {
+                    ubyte bb = @(pixptr) >> bitnr       ; extract bit
+                    ror(bits)           ; shift it into the byte
+                    pixptr += bitplane_stride
+                }
+                bits >>= 8-num_planes
+                cx16.FB_set_pixel(bits)
+            }
+        }
+    }
+}

examples/cx16/imageviewer/imageviewer.p8

@@ -0,0 +1,197 @@
+%target cx16
+%import graphics
+%import textio
+%import diskio
+%import koala_module
+%import iff_module
+%import pcx_module
+%import bmp_module
+;; %import ci_module
+
+main {
+    sub start() {
+        ; trick to check if we're running on sdcard or host system shared folder
+        txt.print("\nimage viewer for commander x16\nformats supported: .iff, .pcx, .bmp, .koa (c64 koala)\n\n")
+        if strlen(diskio.status(8)) {
+            txt.print("enter image file name or just enter for all on disk: ")
+            ubyte i = txt.input_chars(diskio.filename)
+            graphics.enable_bitmap_mode()
+            if i
+                attempt_load(diskio.filename)
+            else
+                show_pics_sdcard()
+
+            txt.print("\nnothing more to do.\n")
+        }
+        else
+            txt.print("files are read with sequential file loading.\nin the emulator this currently only works with files on an sd-card image.\nsorry :(\n")
+
+        repeat {
+            ;
+        }
+    }
+
+    sub show_pics_sdcard() {
+
+        ; load and show the images on the disk with the given extensions.
+        ; this only works in the emulator V38 with an sd-card image with the files on it.
+
+        str[40] filename_ptrs
+        ubyte num_files = diskio.list_files(8, 0, false, &filename_ptrs, len(filename_ptrs))
+        if num_files {
+            while num_files {
+                num_files--
+                attempt_load(filename_ptrs[num_files])
+            }
+        } else
+            txt.print("no files in directory!\n")
+
+    }
+
+    sub attempt_load(uword filenameptr) {
+        txt.print(">> ")
+        txt.print(filenameptr)
+        txt.chrout('\n')
+        uword extension = filenameptr + rfind(filenameptr, '.')
+        if strcmp(extension, ".iff")==0 {
+            txt.print("loading ")
+            txt.print("iff\n")
+            if iff_module.show_image(filenameptr)
+                txt.clear_screen()
+            else
+                txt.print("load error!\n")
+            cx16.wait(120)
+        }
+        else if strcmp(extension, ".pcx")==0 {
+            txt.print("loading ")
+            txt.print("pcx\n")
+            if pcx_module.show_image(filenameptr)
+                txt.clear_screen()
+            else
+                txt.print("load error!\n")
+            cx16.wait(120)
+        }
+        else if strcmp(extension, ".koa")==0 {
+            txt.print("loading ")
+            txt.print("koala\n")
+            if koala_module.show_image(filenameptr)
+                txt.clear_screen()
+            else
+                txt.print("load error!\n")
+            cx16.wait(120)
+        }
+        else if strcmp(extension, ".bmp")==0 {
+            txt.print("loading ")
+            txt.print("bmp\n")
+            if bmp_module.show_image(filenameptr)
+                txt.clear_screen()
+            else
+                txt.print("load error!\n")
+            cx16.wait(120)
+        }
+;        else if strcmp(extension, ".ci")==0 {
+;            txt.print("loading ")
+;            txt.print("ci\n")
+;            if ci_module.show_image(filenameptr)
+;                txt.clear_screen()
+;            else
+;                txt.print("load error!\n")
+;            cx16.wait(120)
+;        }
+    }
+
+    sub extension_equals(uword stringptr, uword extensionptr) -> ubyte {
+        ubyte ix = rfind(stringptr, '.')
+        return ix<255 and strcmp(stringptr+ix, extensionptr)==0
+    }
+
+    sub rfind(uword stringptr, ubyte char) -> ubyte {
+        ubyte i
+        for i in strlen(stringptr)-1 downto 0 {
+            if @(stringptr+i)==char
+                return i
+        }
+        return 0
+    }
+
+}
+
+palette {
+
+    sub set_rgb4(uword palletteptr, uword num_colors) {
+        ; 2 bytes per color entry, the Vera uses this, but the R/GB bytes order is swapped
+        uword vera_palette_ptr = $fa00
+        repeat num_colors {
+            cx16.vpoke(1, vera_palette_ptr+1, @(palletteptr))
+            palletteptr++
+            cx16.vpoke(1, vera_palette_ptr, @(palletteptr))
+            palletteptr++
+            vera_palette_ptr+=2
+        }
+    }
+
+    sub set_rgb8(uword palletteptr, uword num_colors) {
+        ; 3 bytes per color entry, adjust color depth from 8 to 4 bits per channel.
+        uword vera_palette_ptr = $fa00
+        ubyte red
+        ubyte greenblue
+        repeat num_colors {
+            red = @(palletteptr) >> 4
+            palletteptr++
+            greenblue = @(palletteptr) & %11110000
+            palletteptr++
+            greenblue |= @(palletteptr) >> 4    ; add Blue
+            palletteptr++
+            cx16.vpoke(1, vera_palette_ptr, greenblue)
+            vera_palette_ptr++
+            cx16.vpoke(1, vera_palette_ptr, red)
+            vera_palette_ptr++
+        }
+    }
+
+    sub set_bgra(uword palletteptr, uword num_colors) {
+        uword vera_palette_ptr = $fa00
+        ubyte red
+        ubyte greenblue
+
+        ; 4 bytes per color entry (BGRA), adjust color depth from 8 to 4 bits per channel.
+        repeat num_colors {
+            red = @(palletteptr+2) >> 4
+            greenblue = @(palletteptr+1) & %11110000
+            greenblue |= @(palletteptr+0) >> 4    ; add Blue
+            palletteptr+=4
+            cx16.vpoke(1, vera_palette_ptr, greenblue)
+            vera_palette_ptr++
+            cx16.vpoke(1, vera_palette_ptr, red)
+            vera_palette_ptr++
+        }
+    }
+
+    sub set_monochrome() {
+        uword vera_palette_ptr = $fa00
+        cx16.vpoke(1, vera_palette_ptr, 0)
+        vera_palette_ptr++
+        cx16.vpoke(1, vera_palette_ptr, 0)
+        vera_palette_ptr++
+        repeat 255 {
+            cx16.vpoke(1, vera_palette_ptr, 255)
+            vera_palette_ptr++
+            cx16.vpoke(1, vera_palette_ptr, 255)
+            vera_palette_ptr++
+        }
+    }
+
+    sub set_grayscale() {
+        ubyte c = 0
+        uword vera_palette_ptr = $fa00
+        repeat 16 {
+            repeat 16 {
+                cx16.vpoke(1, vera_palette_ptr, c)
+                vera_palette_ptr++
+                cx16.vpoke(1, vera_palette_ptr, c)
+                vera_palette_ptr++
+            }
+            c += $11
+        }
+    }
+}

examples/cx16/imageviewer/koala_module.p8

@@ -1,62 +1,28 @@
 %target cx16
 %import graphics
-%import textio
 %import diskio
 %import c64colors
 
-main {
-    const uword load_location = $4000
+koala_module {
+    const uword load_location = $6000
 
-    sub start() {
-
-        str[] pictures = [
-            "i01-blubb-sphinx.bin",
-            "i02-bugjam-jsl.bin",
-            "i03-dinothawr-ar.bin",
-            "i04-fox-leon.bin",
-            "i05-hunter-agod.bin",
-            "i06-jazzman-jds.bin",
-            "i07-katakis-jegg.bin"
-        ]
-
-        ; set a better C64 color palette, the Cx16's default is too saturated
-        c64colors.set_palette_pepto()
-        graphics.enable_bitmap_mode()
-        repeat {
-            ubyte file_idx
-            for file_idx in 0 to len(pictures)-1 {
-                load_image(pictures[file_idx])
-                wait()
+    sub show_image(uword filenameptr) -> ubyte {
+        ubyte load_ok=false
+        if diskio.f_open(8, filenameptr) {
+            uword size = diskio.f_read(load_location, 2)    ; skip the first 2 bytes (load address)
+            if size==2 {
+                size = diskio.f_read(load_location, 10001)
+                if size == 10001 {
+                    ; set a better C64 color palette, the Cx16's default is too saturated
+                    c64colors.set_palette_pepto()
+                    convert_koalapic()
+                    load_ok = true
+                }
             }
+            diskio.f_close()
         }
-    }
 
-    sub wait() {
-        uword jiffies = 0
-        c64.SETTIM(0,0,0)
-
-        while jiffies < 180 {
-            ; read clock
-            %asm {{
-                stx  P8ZP_SCRATCH_REG
-                jsr  c64.RDTIM
-                sta  jiffies
-                stx  jiffies+1
-                ldx  P8ZP_SCRATCH_REG
-            }}
-        }
-    }
-
-    sub load_image(uword filenameptr) {
-        uword length = diskio.load(8, filenameptr, load_location)
-
-        if length != 10001 {
-            txt.print_uw(length)
-            txt.print("\nload error\n")
-            diskio.status(8)
-            exit(1)
-        }
-        convert_koalapic()
+        return load_ok
     }
 
     sub convert_koalapic() {
@@ -69,6 +35,8 @@ main {
         ; theoretically you could put the 8-pixel array in zeropage to squeeze out another tiny bit of performance
         ubyte[8] pixels
 
+        graphics.clear_screen(1, 0)
+
         for cy in 0 to 24*8 step 8 {
             for cx in 0 to 39 {
                 for d in 0 to 7 {

examples/cx16/imageviewer/pcx_module.p8

@@ -0,0 +1,180 @@
+%target cx16
+%import graphics
+%import textio
+%import diskio
+
+pcx_module {
+
+    sub show_image(uword filenameptr) -> ubyte {
+        ubyte load_ok = false
+
+        if diskio.f_open(8, filenameptr) {
+            ubyte[128] header
+            uword size = diskio.f_read(header, 128)
+            if size==128 {
+                if header[0] == $0a and header[2] == 1 {
+                    ubyte bits_per_pixel = header[3]
+                    if bits_per_pixel==1 or bits_per_pixel==4 or bits_per_pixel==8 {
+                        uword width = mkword(header[$09], header[$08]) - mkword(header[$05], header[$04]) + 1
+                        uword height = mkword(header[$0b], header[$0a]) - mkword(header[$07], header[$06]) + 1
+                        ubyte number_of_planes = header[$41]
+                        uword palette_format = mkword(header[$45], header[$44])
+                        uword num_colors = 2**bits_per_pixel
+                        if number_of_planes == 1 {
+                            if (width & 7) == 0 {
+                                graphics.clear_screen(1, 0)
+                                if palette_format==2
+                                    palette.set_grayscale()
+                                else if num_colors == 16
+                                    palette.set_rgb8(&header + $10, 16)
+                                else if num_colors == 2
+                                    palette.set_monochrome()
+                                when bits_per_pixel {
+                                    8 -> load_ok = bitmap.do8bpp(width, height)
+                                    4 -> load_ok = bitmap.do4bpp(width, height)
+                                    1 -> load_ok = bitmap.do1bpp(width, height)
+                                }
+                                if load_ok {
+                                    load_ok = c64.CHRIN()
+                                    if load_ok == 12 {
+                                        ; there is 256 colors of palette data at the end
+                                        uword palette_mem = progend()
+                                        load_ok = false
+                                        size = diskio.f_read(palette_mem, 3*256)
+                                        if size==3*256 {
+                                            load_ok = true
+                                            palette.set_rgb8(palette_mem, num_colors)
+                                        }
+                                    }
+                                }
+                            } else
+                                txt.print("width not multiple of 8!\n")
+                        } else
+                            txt.print("has >256 colors!\n")
+                    }
+                }
+            }
+            diskio.f_close()
+        }
+
+        return load_ok
+    }
+}
+
+bitmap {
+
+    uword offsetx
+    uword offsety
+    uword py
+    uword px
+    ubyte y_ok
+    ubyte status
+
+    sub start_plot(uword width, uword height) {
+        offsetx = 0
+        offsety = 0
+        y_ok = true
+        py = 0
+        px = 0
+        if width < graphics.WIDTH
+            offsetx = (graphics.WIDTH - width - 1) / 2
+        if height < graphics.HEIGHT
+            offsety = (graphics.HEIGHT - height - 1) / 2
+        status = (not c64.READST()) or c64.READST()==64
+    }
+
+    sub set_cursor(uword x, uword y) {
+        cx16.r0=offsetx+x
+        cx16.r1=offsety+y
+        cx16.FB_cursor_position()
+    }
+
+    sub next_scanline() {
+        px = 0
+        py++
+        y_ok = py < graphics.HEIGHT-1
+        set_cursor(0, py)
+        status = (not c64.READST()) or c64.READST()==64
+    }
+
+    sub do1bpp(uword width, uword height) -> ubyte {
+        start_plot(width, height)
+        set_cursor(0, 0)
+        while py < height and status {
+            ubyte b = c64.CHRIN()
+            if b>>6==3 {
+                b &= %00111111
+                ubyte dat = c64.CHRIN()
+                repeat b {
+                    if y_ok {
+                        cx16.r0 = dat
+                        cx16.FB_set_8_pixels_opaque(255, 255, 0)
+                    }
+                    px += 8
+                }
+            } else {
+                if y_ok {
+                    cx16.r0 = b
+                    cx16.FB_set_8_pixels_opaque(255, 255, 0)
+                }
+                px += 8
+            }
+            if px==width
+                next_scanline()
+        }
+
+        return status
+    }
+
+    sub do4bpp(uword width, uword height) -> ubyte {
+        start_plot(width, height)
+        set_cursor(0, 0)
+        while py < height and status {
+            ubyte b = c64.CHRIN()
+            if b>>6==3 {
+                b &= %00111111
+                ubyte dat = c64.CHRIN()
+                if y_ok
+                    repeat b {
+                        cx16.FB_set_pixel(dat>>4)
+                        cx16.FB_set_pixel(dat & 15)
+                    }
+                px += b*2
+            } else {
+                if y_ok {
+                    cx16.FB_set_pixel(b>>4)
+                    cx16.FB_set_pixel(b & 15)
+                }
+                px += 2
+            }
+            if px==width
+                next_scanline()
+        }
+
+        return status
+    }
+
+    sub do8bpp(uword width, uword height) -> ubyte {
+        start_plot(width, height)
+        set_cursor(0, 0)
+        while py < height and status {
+            ubyte b = c64.CHRIN()
+            if b>>6==3 {
+                b &= %00111111
+                ubyte dat = c64.CHRIN()
+                if y_ok
+                    repeat b
+                        cx16.FB_set_pixel(dat)
+                px += b
+            } else {
+                if y_ok
+                    cx16.FB_set_pixel(b)
+                px++
+            }
+            if px==width
+                next_scanline()
+        }
+
+        return status
+    }
+}

examples/cx16/simplegraphics.p8

@@ -1,40 +0,0 @@
-; CommanderX16 simple graphics example!
-
-%target cx16
-%zeropage basicsafe
-
-
-main {
-
-    sub start() {
-
-        void cx16.screen_set_mode($80)
-        cx16.r0=0
-        void cx16.screen_set_mode(0)
-
-        cx16.FB_init()
-        cx16.GRAPH_init()
-        cx16.r0 = 0
-        cx16.r1 = 0
-        cx16.FB_cursor_position()
-        ubyte color
-        repeat 320*199 {
-            cx16.FB_set_pixel(color)
-            color++
-        }
-
-        uword xx
-        for xx in 0 to 319 step 32 {
-            ubyte q
-            for q in 0 to 31 {
-                cx16.GRAPH_set_colors(q, 2, 0)
-                cx16.r0 = xx+q
-                cx16.r1=0
-                cx16.r2=rnd()
-                cx16.r3=199
-                cx16.GRAPH_draw_line()
-            }
-        }
-    }
-}
-

examples/dirlist.p8

@@ -6,6 +6,9 @@
 
 main {
     sub start() {
+        txt.print("showing the full directory of drive 8:\n")
+        void diskio.directory(8)
+        txt.chrout('\n')
 
         if diskio.lf_start_list(8, "cub", false) {
             txt.print("\nfiles starting with 'cub':\n")

examples/test.p8

@@ -1,23 +1,13 @@
 %import textio
 %import diskio
 %import floats
+%import graphics
 %zeropage basicsafe
 %import test_stack
 %option no_sysinit
 
 main {
-    sub start() {
-        ubyte[] barr = [0,0,0]
-        uword[] warr = [0,0,0]
-
-        ubyte xx = 0
-        barr[1] = xx+9
-        warr[1] = &warr
-
-        txt.print_ub(barr[1])
-        txt.chrout('\n')
-        txt.print_uwhex(warr[1],1 )
-        txt.chrout('\n')
+    sub start () {
 
         test_stack.test()
     }

syntax-files/IDEA/Prog8.xml

@@ -14,7 +14,7 @@
     <keywords keywords="&amp;;-&gt;;@;\$;and;as;asmsub;break;clobbers;continue;do;downto;else;false;for;goto;if;if_cc;if_cs;if_eq;if_mi;if_ne;if_neg;if_nz;if_pl;if_pos;if_vc;if_vs;if_z;in;not;or;repeat;return;romsub;step;sub;to;true;until;when;while;xor;~" ignore_case="false" />
     <keywords2 keywords="%address;%asm;%asmbinary;%asminclude;%breakpoint;%import;%launcher;%option;%output;%target;%zeropage;%zpreserved" />
     <keywords3 keywords="byte;const;float;str;struct;ubyte;uword;void;word;zp" />
-    <keywords4 keywords="abs;acos;all;any;asin;atan;avg;ceil;clear_carry;clear_irqd;cos;cos16;cos16u;cos8;cos8u;deg;exit;floor;leftstr;len;ln;log2;lsb;lsl;lsr;max;memcopy;memset;memsetw;min;mkword;msb;rad;read_flags;reverse;rightstr;rnd;rndf;rndw;rol;rol2;ror;ror2;round;rrestore;rsave;set_carry;set_irqd;sgn;sin;sin16;sin16u;sin8;sin8u;sizeof;sort;sqrt;sqrt16;strcmp;strlen;substr;sum;swap;tan" />
+    <keywords4 keywords="abs;acos;all;any;asin;atan;avg;ceil;clear_carry;clear_irqd;cos;cos16;cos16u;cos8;cos8u;deg;exit;floor;leftstr;len;ln;log2;lsb;lsl;lsr;max;memcopy;memset;memsetw;min;mkword;msb;progend;rad;read_flags;reverse;rightstr;rnd;rndf;rndw;rol;rol2;ror;ror2;round;rrestore;rsave;set_carry;set_irqd;sgn;sin;sin16;sin16u;sin8;sin8u;sizeof;sort;sqrt;sqrt16;strcmp;strlen;substr;sum;swap;tan" />
   </highlighting>
   <extensionMap>
     <mapping ext="p8" />

syntax-files/IDEA/readme.txt

@@ -6,3 +6,6 @@ The exact path may vary with the version of the IDE,
 but for me it is currently this on Linux:
 
 $HOME/.config/JetBrains/IntelliJIdea2020.2/filetypes/
+
+
+(note the version number in the path, adjust accordingly)