diff --git a/picoc.c b/picoc.c
index fd2d73a..5095e5f 100644
--- a/picoc.c
+++ b/picoc.c
@@ -46,19 +46,23 @@ int picoc(char *SourceStr)
     int ix;
     
     Initialise();
-    for (ix=0; ix<strlen(SourceStr); ix++)  // clear out ctrl-z from XMODEM transfer
-        if (SourceStr[ix] == 0x1A)
-            SourceStr[ix] = 0x20;
-    printf("%s\n\r", SourceStr);  // display program source
-    printf("=====================\n");
+    if (SourceStr) {
+        for (ix=0; ix<strlen(SourceStr); ix++)  // clear out ctrl-z from XMODEM transfer
+            if (SourceStr[ix] == 0x1A)
+                SourceStr[ix] = 0x20;
+        printf("%s\n\r", SourceStr);  // display program source
+        printf("=====================\n");
+    }
     errjmp[40] = 0;
     setjmp(errjmp);
     if (errjmp[40]) {
-        printf("goodbye ...\n\r");
+        printf("leaving picoC\n\r");
         return 1;
     }
         
-    Parse("test.c", SourceStr, strlen(SourceStr), TRUE);
+    if (SourceStr)    
+        Parse("test.c", SourceStr, strlen(SourceStr), TRUE);
+    ParseInteractive();
     return 0;
 }
 # endif
diff --git a/platform_library.c b/platform_library.c
index 0c98390..005a620 100644
--- a/platform_library.c
+++ b/platform_library.c
@@ -349,92 +349,182 @@ void Ctan(struct ParseState *Parser, struct Value *ReturnValue, struct Value **P
 void Casin(struct ParseState *Parser, struct Value *ReturnValue, struct Value **Param, int NumArgs)  // asin(y,hyp)
 {
     int y, hyp, quot, sgn, ix;
-	y = Param[0]->Val->Integer;
-	hyp = Param[1]->Val->Integer;
+    y = Param[0]->Val->Integer;
+    hyp = Param[1]->Val->Integer;
     if (y > hyp)
         ProgramFail(NULL, "asin():  opposite greater than hypotenuse");
-	if (y == 0) {
+    if (y == 0) {
         ReturnValue->Val->Integer = 0;
-	    return;
-	}
-	sgn = hyp * y;
-	if (hyp < 0) 
-	    hyp = -hyp;
-	if (y < 0)
-	    y = -y;
-	quot = (y * 10000) / hyp;
-	if (quot > 9999)
-	    quot = 9999;
-	for (ix=0; ix<90; ix++)
-	    if ((quot < cosine[ix]) && (quot >= cosine[ix+1]))
-	        break;
-	if (sgn < 0)
-	    ReturnValue->Val->Integer = -(90-ix);
-	else
-	    ReturnValue->Val->Integer = 90-ix;
+        return;
+    }
+    sgn = hyp * y;
+    if (hyp < 0) 
+        hyp = -hyp;
+    if (y < 0)
+        y = -y;
+    quot = (y * 10000) / hyp;
+    if (quot > 9999)
+        quot = 9999;
+    for (ix=0; ix<90; ix++)
+        if ((quot < cosine[ix]) && (quot >= cosine[ix+1]))
+            break;
+    if (sgn < 0)
+        ReturnValue->Val->Integer = -(90-ix);
+    else
+        ReturnValue->Val->Integer = 90-ix;
 }
 
 void Cacos(struct ParseState *Parser, struct Value *ReturnValue, struct Value **Param, int NumArgs)  // acos(x,hyp)
 {
     int x, hyp, quot, sgn, ix;
-	x = Param[0]->Val->Integer;
-	hyp = Param[1]->Val->Integer;
+    x = Param[0]->Val->Integer;
+    hyp = Param[1]->Val->Integer;
     if (x > hyp)
         ProgramFail(NULL, "acos():  adjacent greater than hypotenuse");
-	if (x == 0) {
-	    if (hyp < 0)
+    if (x == 0) {
+        if (hyp < 0)
             ReturnValue->Val->Integer = -90;
         else
             ReturnValue->Val->Integer = 90;
-	    return;
-	}
-	sgn = hyp * x;
-	if (hyp < 0) 
-	    hyp = -hyp;
-	if (x < 0)
-	    x = -x;
-	quot = (x * 10000) / hyp;
-	if (quot > 9999)
-	    quot = 9999;
-	for (ix=0; ix<90; ix++)
-	    if ((quot < cosine[ix]) && (quot >= cosine[ix+1]))
-	        break;
-	if (sgn < 0)
-	    ReturnValue->Val->Integer = -ix;
-	else
-	    ReturnValue->Val->Integer = ix;
+        return;
+    }
+    sgn = hyp * x;
+    if (hyp < 0) 
+        hyp = -hyp;
+    if (x < 0)
+        x = -x;
+    quot = (x * 10000) / hyp;
+    if (quot > 9999)
+        quot = 9999;
+    for (ix=0; ix<90; ix++)
+        if ((quot < cosine[ix]) && (quot >= cosine[ix+1]))
+            break;
+    if (sgn < 0)
+        ReturnValue->Val->Integer = -ix;
+    else
+        ReturnValue->Val->Integer = ix;
 }
 
 void Catan(struct ParseState *Parser, struct Value *ReturnValue, struct Value **Param, int NumArgs)  // atan(y,x)
 {
     int x,y, angle, coeff_1, coeff_2, r;
-	y = Param[0]->Val->Integer;
-	x = Param[1]->Val->Integer;
-	if (x == 0) {
-	    if (y >= 0)
-	        ReturnValue->Val->Integer = 90;
-	    else
-	        ReturnValue->Val->Integer = -90;
-	    return;
-	}
-	coeff_1 = 3141/4;
-	coeff_2 = coeff_1*3;
+    y = Param[0]->Val->Integer;
+    x = Param[1]->Val->Integer;
+    if (x == 0) {
+        if (y >= 0)
+            ReturnValue->Val->Integer = 90;
+        else
+            ReturnValue->Val->Integer = -90;
+        return;
+    }
+    coeff_1 = 3141/4;
+    coeff_2 = coeff_1*3;
     if (y < 0)
         y = -y;
-	if (x >= 0) {
-		r = (x - y)*1000 / (x + y);
-		angle = (coeff_1*1000 - coeff_1 * r);
-	} else {
-		r = (x + y)*1000 / (y - x);
-		angle = (coeff_2*1000 - coeff_1 * r);
-	}
-	angle = angle*57/1000000;
-	if (y < 0)
-	    ReturnValue->Val->Integer = -angle;
-	else
-	    ReturnValue->Val->Integer = angle;
+    if (x >= 0) {
+        r = (x - y)*1000 / (x + y);
+        angle = (coeff_1*1000 - coeff_1 * r);
+    } else {
+        r = (x + y)*1000 / (y - x);
+        angle = (coeff_2*1000 - coeff_1 * r);
+    }
+    angle = angle*57/1000000;
+    if (y < 0)
+        ReturnValue->Val->Integer = -angle;
+    else
+        ReturnValue->Val->Integer = angle;
 } 
 
+void Cnnset(struct ParseState *Parser, struct Value *ReturnValue, struct Value **Param, int NumArgs) {
+    int ix, i1;
+    
+    ix = Param[0]->Val->Integer;
+    if (ix > NUM_NPATTERNS)
+        ProgramFail(NULL, "nnset():  invalid index");
+    for (i1=0; i1<8; i1++)
+        npattern[ix*8 + i1] = (unsigned char)Param[i1+1]->Val->Integer;
+}
+
+void Cnnshow(struct ParseState *Parser, struct Value *ReturnValue, struct Value **Param, int NumArgs) {
+    int ix;
+    
+    ix = Param[0]->Val->Integer;
+    if (ix > NUM_NPATTERNS)
+        ProgramFail(NULL, "nnshow():  invalid index");
+    nndisplay(ix);
+}
+
+void Cnninit(struct ParseState *Parser, struct Value *ReturnValue, struct Value **Param, int NumArgs) {
+    nninit_network();
+}
+
+void Cnntrain(struct ParseState *Parser, struct Value *ReturnValue, struct Value **Param, int NumArgs) {
+    int ix, i1;
+
+    nntrain_network(10000);
+    for (ix=0; ix<NUM_NPATTERNS; ix++) {
+        nnset_pattern(ix);
+        nncalculate_network();
+        for (i1=0; i1<NUM_OUTPUT; i1++) 
+            printf(" %3d", N_OUT(i1)/10);
+        printf("\n\r");
+    }
+}
+
+void Cnntest(struct ParseState *Parser, struct Value *ReturnValue, struct Value **Param, int NumArgs) {
+    int ix, i1, i2;
+    unsigned char ch;
+    
+    ix = 0;
+    for (i1=0; i1<8; i1++) {
+        ch = (unsigned char)Param[i1]->Val->Integer;
+        for (i2=0; i2<8; i2++) {
+            if (ch & nmask[i2])
+                N_IN(ix++) = 1024;
+            else
+                N_IN(ix++) = 0;
+        }
+    }
+    nncalculate_network();
+    for (i1=0; i1<NUM_OUTPUT; i1++) 
+        printf(" %3d", N_OUT(i1)/10);
+    printf("\n\r");
+}
+
+void Cnnmatchblob(struct ParseState *Parser, struct Value *ReturnValue, struct Value **Param, int NumArgs) {            
+    int ix, i1;
+    
+    ix = Param[0]->Val->Integer;
+    if (ix > MAX_BLOBS)
+        ProgramFail(NULL, "nnmatchblob():  invalid blob index");
+    if (!blobcnt[ix])
+        ProgramFail(NULL, "nnmatchblob():  not a valid blob");
+    /* use data still in blob_buf[] (FRAME_BUF3)
+       square the aspect ratio of x1, x2, y1, y2
+       then subsample blob pixels to populate N_IN(0:63) with 0:1024 values
+       then nncalculate_network() and display the N_OUT() results */
+    nnscale8x8((unsigned char *)FRAME_BUF3, blobix[ix], blobx1[ix], blobx2[ix], 
+            bloby1[ix], bloby2[ix], imgWidth, imgHeight);
+    nncalculate_network();
+    for (i1=0; i1<NUM_OUTPUT; i1++) 
+        printf(" %3d", N_OUT(i1)/10);
+    printf("\n\r");
+}
+
+void Cnnlearnblob (struct ParseState *Parser, struct Value *ReturnValue, struct Value **Param, int NumArgs) {
+    int ix;
+    
+    ix = Param[0]->Val->Integer;
+    if (ix > NUM_NPATTERNS)
+        ProgramFail(NULL, "nnlearnblob():  invalid index");
+    if (!blobcnt[0])
+        ProgramFail(NULL, "nnlearnblob():  no blob to grab");
+    nnscale8x8((unsigned char *)FRAME_BUF3, blobix[0], blobx1[0], blobx2[0], 
+            bloby1[0], bloby2[0], imgWidth, imgHeight);
+    nnpack8x8(ix);
+    nndisplay(ix);
+}
+
 /* list of all library functions and their prototypes */
 struct LibraryFunction PlatformLibrary[] =
 {
@@ -458,7 +548,7 @@ struct LibraryFunction PlatformLibrary[] =
     { Cvpix,        "void vpix(int, int)" },
     { Cvmean,       "void vmean()" },
     { Cvblob,       "int vblob(int, int)" },
-    { Ccompass,     "int compass(int)" },
+    { Ccompass,     "int compass()" },
     { Creadi2c,     "int readi2c(int, int)" },
     { Creadi2c2,    "int readi2c2(int, int)" },
     { Cwritei2c,    "void writei2c(int, int, int)" },
@@ -468,6 +558,13 @@ struct LibraryFunction PlatformLibrary[] =
     { Casin,        "int asin(int, int)" },
     { Cacos,        "int acos(int, int)" },
     { Catan,        "int atan(int, int)" },
+    { Cnnshow,      "void nnshow(int)" },
+    { Cnnset,       "void nnset(int, int, int, int, int, int, int, int, int)" },
+    { Cnninit,      "void nninit()" },
+    { Cnntrain,     "void nntrain()" },
+    { Cnntest,      "void nntest(int, int, int, int, int, int, int, int)" },
+    { Cnnmatchblob, "void nnmatchblob(int)" },
+    { Cnnlearnblob, "void nnlearnblob(int)" },
     { NULL,         NULL }
 };
 #endif
diff --git a/platform_support.c b/platform_support.c
index 721832e..745cbe6 100644
--- a/platform_support.c
+++ b/platform_support.c
@@ -68,6 +68,25 @@ void PlatformExit()
 /* get a line of interactive input */
 char *PlatformGetLine(char *Buf, int MaxLen)
 {
+    int ix;
+    char ch, *cp;
+    
+    ix = 0;
+    cp = Buf;
+    while (ix++ < MaxLen) {
+        ch = getch();
+        if (ch == 0x1B) { // ESC character - exit
+            printf("leaving picoC\n\r");
+            return NULL;
+        }
+        if (ch == '\n') {
+            *cp++ = '\n';  // if newline, send newline character followed by null
+            *cp = 0;
+            return Buf;
+        }
+        *cp++ = ch;
+        ix++;
+    }
     return NULL;
 }