diff --git a/assets/basic.js b/assets/basic.js
index f273696..dbea20d 100644
--- a/assets/basic.js
+++ b/assets/basic.js
@@ -16,6 +16,7 @@ Test Programs:
 
 */
 let INDEX_BASE = 0;
+let TRACEON = true;
 
 if (system.maxmem() < 8192) {
     println("Out of memory. BASIC requires 8K or more User RAM");
@@ -327,7 +328,7 @@ let ForGen = function(s,e,t) {
     // returns undefined if there is no next()
     this.getNext = function(mutated) {
         //if (mutated === undefined) throw "InternalError: parametre is missing";
-        if (mutated !== undefined) this.current = mutated;
+        if (mutated !== undefined) this.current = (mutated|0);
         this.current += this.step;
         return this.hasNext() ? this.current : undefined;
     }
@@ -575,12 +576,16 @@ if no arg text were given (e.g. "10 NEXT"), args will have zero length
             var rsvArg = resolve(args[llll]);
             if (rsvArg === undefined && args[llll] !== undefined && args[llll].troType != "null") throw lang.refError(lnum, args[llll].troValue);
 
+            let printstr = "";
             if (rsvArg === undefined)
-                print("");
+                printstr = ("");
             else if (rsvArg.toString !== undefined)
-                print(rsvArg.toString());
+                printstr = (rsvArg.toString());
             else
-                print(rsvArg);
+                printstr = (rsvArg);
+
+            print(printstr);
+            if (TRACEON) serial.println("[BASIC.PRINT] "+printstr);
         }
     }
 
@@ -731,6 +736,9 @@ if no arg text were given (e.g. "10 NEXT"), args will have zero length
         if (forVarname === undefined) {
             throw lang.nextWithoutFor(lnum);
         }
+
+        if (TRACEON) serial.println("[BASIC.FOR] looping "+forVarname);
+
         var forVar = bStatus.vars["for var "+forVarname].bvLiteral;
 
         if (forVar instanceof ForGen)
@@ -755,6 +763,18 @@ if no arg text were given (e.g. "10 NEXT"), args will have zero length
 
     throw lang.syntaxfehler(lnum, "extra arguments for NEXT");
 },
+"BREAKTO" : function(lnum, args) {
+    return oneArgNum(lnum, args, (lh) => {
+        var forVarname = bStatus.forStack.pop();
+        if (forVarname === undefined) {
+            throw lang.nextWithoutFor(lnum);
+        }
+        if (TRACEON) serial.println(`[BASIC.FOR] breaking from ${forVarname}, jump to ${lh}`);
+
+        if (lh < 0) throw lang.syntaxfehler(lnum, lh);
+        return lh;
+    });
+},
 /*
 10 input;"what is your name";a$
 
@@ -799,6 +819,8 @@ if no arg text were given (e.g. "10 NEXT"), args will have zero length
     // print out prompt text
     print("? "); var rh = sys.read().trim();
 
+    if (rh*1 === (rh|0) || !isNaN(rh)) rh = rh*1
+
     if (troValue.arrObj !== undefined) {
         if (isNaN(rh) && !Array.isArray(rh)) throw lang.illegalType(lnum, rh);
 
@@ -1664,7 +1686,7 @@ let SyntaxTreeReturnObj = function(type, value, nextLine) {
     this.troValue = value;
     this.troNextLine = nextLine;
 }
-bF._gotoCmds = {GOTO:1,GOSUB:1,RETURN:1,NEXT:1,END:1}; // put nonzero (truthy) value here
+bF._gotoCmds = {GOTO:1,GOSUB:1,RETURN:1,NEXT:1,END:1,BREAKTO:1}; // put nonzero (truthy) value here
 /**
  * @param lnum line number of BASIC
  * @param syntaxTree BasicAST
@@ -1674,7 +1696,7 @@ bF._gotoCmds = {GOTO:1,GOSUB:1,RETURN:1,NEXT:1,END:1}; // put nonzero (truthy) v
  */
 bF._troNOP = function(lnum) { return new SyntaxTreeReturnObj("null", undefined, lnum + 1); }
 bF._executeSyntaxTree = function(lnum, syntaxTree, recDepth) {
-    var _debugExec = true;
+    var _debugExec = false;
     var recWedge = "> ".repeat(recDepth);
 
     if (_debugExec) serial.println(recWedge+"@@ EXECUTE @@");
@@ -1772,7 +1794,12 @@ bF._executeSyntaxTree = function(lnum, syntaxTree, recDepth) {
 };
 // @returns: line number for the next command, normally (lnum + 1); if GOTO or GOSUB was met, returns its line number
 bF._interpretLine = function(lnum, cmd) {
-    var _debugprintHighestLevel = true;
+    var _debugprintHighestLevel = false;
+
+    if (TRACEON) {
+        //print(`[${lnum}]`);
+        serial.println("[BASIC] Line "+lnum);
+    }
 
     if (cmd.toUpperCase().startsWith("REM")) {
         if (_debugprintHighestLevel) serial.println(lnum+" "+cmd);
@@ -1794,13 +1821,16 @@ bF._interpretLine = function(lnum, cmd) {
     if (_debugprintHighestLevel) serial.println(syntaxTree.toString());
 
     // EXECUTE
-    //try {
+    try {
         var execResult = bF._executeSyntaxTree(lnum, syntaxTree, 0);
         return execResult.troNextLine;
-    //}
-    //catch (e) {
-    //    throw lang.parserError(lnum, e);
-    //}
+    }
+    catch (e) {
+        serial.println(`ERROR on ${lnum} -- PARSE TREE:`);
+        serial.println(syntaxTree.toString());
+        serial.println("ERROR CONTENTS:");
+        println(e);
+    }
 }; // end INTERPRETLINE
 bF._basicList = function(v, i, arr) {
     if (i < 10) print(" ");
@@ -1854,6 +1884,9 @@ bF.renum = function(args) { // RENUM function
         else if (newcmdbuf[k] !== undefined && newcmdbuf[k].toLowerCase().startsWith("gosub ")) {
             newcmdbuf[k] = "GOSUB " + linenumRelation[newcmdbuf[k].match(reNum)[0]];
         }
+        else if (newcmdbuf[k] !== undefined && newcmdbuf[k].toLowerCase().startsWith("breakto ")) {
+            newcmdbuf[k] = "BREAKTO " + linenumRelation[newcmdbuf[k].match(reNum)[0]];
+        }
     }
     cmdbuf = newcmdbuf.slice(); // make shallow copy
 
diff --git a/assets/blackjack.bas b/assets/blackjack.bas
index 5cff2c2..f670266 100644
--- a/assets/blackjack.bas
+++ b/assets/blackjack.bas
@@ -4,7 +4,6 @@
 6 PRINT
 7 PRINT
 8 PRINT
-10 REM DEFUN A(Q)=Q+11*(Q>=22)
 20 HANDS=DIM(15,12)
 21 HANDTOTAL=DIM(15)
 22 DECK=DIM(52)
@@ -22,11 +21,11 @@
 100 REM--SUBROUTINE TO GET A CARD.  RESULT IS PUT IN X.
 110 IF C<51 THEN GOTO 230
 120 PRINT "RESHUFFLING"
-130 FOR DI=D TO 1
+130 FOR D=D TO 1 STEP -1
 140   C=C-1
-150   DECK(C)=DISCARDECK(DI)
+150   DECK(C)=DISCARDECK(D)
 160 NEXT
-170 FOR C1=52 TO C
+170 FOR C1=52 TO C STEP -1
 180   C2=INT(RND(1)*(C1-C+1))+C
 190   C3=DECK(C2)
 200   DECK(C2)=DECK(C1)
@@ -124,7 +123,7 @@
 1420 INPUT HSTR
 1421 HSTR=LEFT(HSTR,1)
 1430 FOR H=1 TO H1 STEP 2
-1440   IF HSTR==MID(ISTR,H,1) THEN GOTO 1480
+1440   IF HSTR==MID(ISTR,H,1) THEN BREAKTO 1480
 1450 NEXT
 1460 PRINT "TYPE ";MID(ISTR,1,H1-1);" OR ";MID(ISTR,H1,2);" PLEASE";
 1470 GOTO 1420
@@ -132,7 +131,7 @@
 1490 RETURN
 1500 REM--PROGRAM STARTS HERE
 1510 REM--INITIALIZE
-1520 DSTR="N A  2  3  4  5  6  7N 8  9 10  J  Q  K"
+1520 DSTR="  A  2  3  4  5  6  7  8  9 10  J  Q  K"
 1530 ISTR="H,S,D,/,"
 1540 FOR I=1 TO 13
 1550   FOR J=4*I-3 TO 4*I
@@ -188,7 +187,7 @@
 1892   INPUT ZARR(I)
 1893 NEXT
 1900 FOR I=1 TO N
-1910   IF ZARR(I)<=0 OR ZARR(I)>500 THEN GOTO 1880
+1910   IF ZARR(I)<=0 OR ZARR(I)>500 THEN BREAKTO 1880
 1920   BETS(I)=ZARR(I)
 1930 NEXT
 1940 PRINT "PLAYER ";
@@ -219,7 +218,7 @@
 2172   INPUT ZARR(I)
 2173 NEXT
 2180 FOR I=1 TO N
-2190   IF ZARR(I)<0 OR ZARR(I)>BETS(I)/2 THEN GOTO 2160
+2190   IF ZARR(I)<0 OR ZARR(I)>BETS(I)/2 THEN BREAKTO 2160
 2200 NEXT
 2210 FOR I=1 TO N
 2220   PLRHNDSUM(I)=ZARR(I)*(3*(-(HANDS(D1,2)>=10))-1)
@@ -233,7 +232,7 @@
 2255 L2=0
 2256 IF L1<>0 OR L2<>0 THEN GOTO 2320
 2260 PRINT
-2261 PRINT "DEALER HAS A";MID(DSTR,3*HANDS(D1,2)-2,3);" IN THE HOLE ";
+2261 PRINT "DEALER HAS";MID(DSTR,3*HANDS(D1,2)-2,3);" IN THE HOLE ";
 2270 PRINT "FOR BLACKJACK"
 2280 FOR I=1 TO D1
 2290   GOSUB 300
@@ -244,8 +243,7 @@
 2340 PRINT
 2341 PRINT "NO DEALER BLACKJACK."
 2350 REM--NOW PLAY THE HANDS
-2360 REM--FOR I=1 TO N--
-2361 I=1
+2360 FOR I=1 TO N
 2370   PRINT "PLAYER ";I;
 2380   H1=7
 2390   GOSUB 1410
@@ -307,20 +305,18 @@
 2870   I=I+D1
 2880   IF I==I1 THEN GOTO 2850
 2890   I=I1-D1
-2900 REM--NEXT I--
-2901 I=I+1
-2902 IF I<=N THEN GOTO 2370
+2900 NEXT
 2910 GOSUB 300
 2920 REM--TEST FOR PLAYING DEALER'S HAND
 2930 FOR I=1 TO N
-2940   IF HANDSLENS(I)>0 OR HANDSLENS(I+D1)>0 THEN GOTO 3010
+2940   IF HANDSLENS(I)>0 OR HANDSLENS(I+D1)>0 THEN BREAKTO 3010
 2950 NEXT
 2960 PRINT "DEALER HAD A";
 2970 X=HANDS(D1,2)
 2980 GOSUB 700
 2990 PRINT " CONCEALED."
 3000 GOTO 3140
-3010 PRINT "DEALER HAS A";MID(DSTR,3*HANDS(D1,2)-2,3);" CONCEALED ";
+3010 PRINT "DEALER HAS";MID(DSTR,3*HANDS(D1,2)-2,3);" CONCEALED ";
 3020 I=D1
 3030 AA=HANDTOTAL(I)
 3031 GOSUB 3400
@@ -333,7 +329,7 @@
 3090 AA=Q
 3091 GOSUB 3400
 3095 IF Q>0 AND AA<17 THEN GOTO 3060
-3100 HANDTOTAL(I)=Q-(Q<0)/2
+3100 HANDTOTAL(I)=(Q-(Q<0)/2)
 3110 IF Q<0 THEN GOTO 3140
 3120 AA=Q
 3121 GOSUB 3400
@@ -343,8 +339,7 @@
 3150 REM 
 3160 ZSTR="LOSES PUSHES WINS "
 3165 PRINT
-3170 REM--FOR I=1 TO N--
-3171 I=1
+3170 FOR I=1 TO N
 3180   AA=HANDTOTAL(I)
 3181   GOSUB 3400
 3182   AB=HANDTOTAL(I+D1)
@@ -360,15 +355,13 @@
 3240   GOTO 3260
 3250   PRINT ABS(PLRHNDSUM(I));
 3260   PLRSUM(I)=PLRSUM(I)+PLRHNDSUM(I)
-3270   PRINT "TOTAL= ";PLRSUM(I)
+3270   PRINT "; TOTAL= ";PLRSUM(I)
 3280   GOSUB 1200
 3290   PLRSUM(D1)=PLRSUM(D1)-PLRHNDSUM(I)
 3300   I=I+D1
 3310   GOSUB 1200
 3320   I=I-D1
-3330 REM--NEXT I--
-3331 I=I+1
-3332 IF I<=N THEN GOTO 3180
+3330 NEXT
 3340 PRINT "DEALER'S TOTAL= ";PLRSUM(D1)
 3345 PRINT
 3350 GOSUB 1200