diff --git a/src/draw.c b/src/draw.c
index 51bc1feb..0f231233 100644
--- a/src/draw.c
+++ b/src/draw.c
@@ -1876,7 +1876,8 @@ static void draw_graph_bus_points(const char *ntok, int n_bits, int *idx_arr,
   double deltag = wy2 - wy1;
   double s1 = DIG_NWAVES; /* 1/DIG_NWAVES  waveforms fit in graph if unscaled vertically */
   double s2 = DIG_SPACE; /* (DIG_NWAVES - DIG_SPACE) spacing between traces */
-  double c = (n_nodes - wcnt) * s1 * deltag - wy1 * s2;
+  double c = (n_nodes - wcnt) * s1 * deltag - wy1 * s2; /* trace baseline */
+  double c1 = c + (wy2 - wy1) * 0.5 * s2; /* trace y-center, used for clipping */
   double x1 = W_X(xctx->graph_values[sweep_idx][first]);
   double x2 = W_X(xctx->graph_values[sweep_idx][last-1]);
   double ylow  = DW_Y(c + wy2 * s2); /* swapped as xschem Y coordinates are top-bottom */
@@ -1887,37 +1888,39 @@ static void draw_graph_bus_points(const char *ntok, int n_bits, int *idx_arr,
   double labsize = 0.015 * ydelta;
   double charwidth = labsize * 38.0;
   double x_size = 1.5 * xctx->zoom;
-  drawline(wave_col, NOW, x1, ylow, x2, ylow, 0);
-  drawline(wave_col, NOW, x1, yhigh, x2, yhigh, 0);
-  for(p = first ; p <= last; p++) {
-    /* calculate value of bus by adding all binary bits */
-    /* hex_digits = */
-    get_bus_value(n_bits, idx_arr, p, busval, wy1, wy2);
-    xval =  W_X(xctx->graph_values[sweep_idx][p]);
-    /* used to draw bus value before 1st transition */
-    if(p == first) {
-      my_strncpy(old_busval, busval, strlen(busval)+1);
-      xval_old = xval;
-    }
-    if(p > first &&  strcmp(busval, old_busval)) {
-      /* draw transition ('X') */
-      drawline(BACKLAYER, NOW, xval-x_size, yhigh, xval+x_size, yhigh, 0);
-      drawline(BACKLAYER, NOW, xval-x_size, ylow,  xval+x_size, ylow, 0);
-      drawline(wave_col, NOW, xval-x_size, ylow,  xval+x_size, yhigh, 0);
-      drawline(wave_col, NOW, xval-x_size, yhigh, xval+x_size, ylow, 0);
-      /* draw hex bus value if there is enough room */
-      if(  fabs(xval - xval_old) > strlen(old_busval) * charwidth) {
-        draw_string(wave_col, NOW, old_busval, 2, 0, 1, 0, (xval + xval_old) * 0.5,
-                    yhigh, labsize, labsize);
+  if(c1 >= ypos1 && c1 <=ypos2) {
+    drawline(wave_col, NOW, x1, ylow, x2, ylow, 0);
+    drawline(wave_col, NOW, x1, yhigh, x2, yhigh, 0);
+    for(p = first ; p <= last; p++) {
+      /* calculate value of bus by adding all binary bits */
+      /* hex_digits = */
+      get_bus_value(n_bits, idx_arr, p, busval, wy1, wy2);
+      xval =  W_X(xctx->graph_values[sweep_idx][p]);
+      /* used to draw bus value before 1st transition */
+      if(p == first) {
+        my_strncpy(old_busval, busval, strlen(busval)+1);
+        xval_old = xval;
       }
-      my_strncpy(old_busval, busval, strlen(busval)+1);
-      xval_old = xval;
-    } /* if(p > first &&  busval != old_busval) */
-  } /* for(p = first ; p < last; p++) */
-  /* draw hex bus value after last transition */
-  if(  fabs(xval - xval_old) > strlen(old_busval) * charwidth) {
-    draw_string(wave_col, NOW, old_busval, 2, 0, 1, 0, (xval + xval_old) * 0.5,
-                yhigh, labsize, labsize);
+      if(p > first &&  strcmp(busval, old_busval)) {
+        /* draw transition ('X') */
+        drawline(BACKLAYER, NOW, xval-x_size, yhigh, xval+x_size, yhigh, 0);
+        drawline(BACKLAYER, NOW, xval-x_size, ylow,  xval+x_size, ylow, 0);
+        drawline(wave_col, NOW, xval-x_size, ylow,  xval+x_size, yhigh, 0);
+        drawline(wave_col, NOW, xval-x_size, yhigh, xval+x_size, ylow, 0);
+        /* draw hex bus value if there is enough room */
+        if(  fabs(xval - xval_old) > strlen(old_busval) * charwidth) {
+          draw_string(wave_col, NOW, old_busval, 2, 0, 1, 0, (xval + xval_old) * 0.5,
+                      yhigh, labsize, labsize);
+        }
+        my_strncpy(old_busval, busval, strlen(busval)+1);
+        xval_old = xval;
+      } /* if(p > first &&  busval != old_busval) */
+    } /* for(p = first ; p < last; p++) */
+    /* draw hex bus value after last transition */
+    if(  fabs(xval - xval_old) > strlen(old_busval) * charwidth) {
+      draw_string(wave_col, NOW, old_busval, 2, 0, 1, 0, (xval + xval_old) * 0.5,
+                  yhigh, labsize, labsize);
+    }
   }
 }
 
@@ -1933,14 +1936,15 @@ static void draw_graph_points(int v, int first, int last,
   double deltag = wy2 - wy1;
   double s1;
   double s2;
-  double c;
+  double c, c1;
 
   if(digital) {
     s1 = DIG_NWAVES; /* 1/DIG_NWAVES  waveforms fit in graph if unscaled vertically */
     s2 = DIG_SPACE; /* (DIG_NWAVES - DIG_SPACE) spacing between traces */
-    c = (n_nodes - wcnt) * s1 * deltag - wy1 * s2;
+    c = (n_nodes - wcnt) * s1 * deltag - wy1 * s2; /* trace baseline */
+    c1 = c + (wy2 - wy1) * 0.5 * s2; /* trace y-center, used for clipping */
   }
-  if( !digital || (c >= ypos1 && c <= ypos2) ) {
+  if( !digital || (c1 >= ypos1 && c1 <= ypos2) ) {
     for(p = first ; p <= last; p++) {
       yy = xctx->graph_values[v][p];
       if(digital) {
diff --git a/src/xschem.h b/src/xschem.h
index ac4618f3..f0051c35 100644
--- a/src/xschem.h
+++ b/src/xschem.h
@@ -338,7 +338,7 @@ do { \
 /* set do double if you need more precision at the expense of memory */
 #define SPICE_DATA float
 #define DIG_NWAVES 0.1  /* inverse number: by default 10 digital traces per graph */
-#define DIG_SPACE 0.08 /* trace extends from 0 to DIG_SPACE, so we have DIG_WAVES-DIG_SPACE
+#define DIG_SPACE 0.07 /* trace extends from 0 to DIG_SPACE, so we have DIG_WAVES-DIG_SPACE
                         * spacing between traces */
 
 typedef struct
diff --git a/xschem_library/rom8k/rom8k.sch b/xschem_library/rom8k/rom8k.sch
index b3740abd..8a836a90 100644
--- a/xschem_library/rom8k/rom8k.sch
+++ b/xschem_library/rom8k/rom8k.sch
@@ -32,8 +32,8 @@ y1 = -0.0039
 y2 = 0.87
 divy = 3
 subdivy=1
-x1=1.5328e-07
-x2=1.84945e-07  divx=10
+x1=1.52536e-07
+x2=1.84201e-07  divx=10
 node="
 ldbl[0] ldbl[16] ldbl[32]
 ldbl[1] ldbl[17] ldbl[33]
@@ -47,8 +47,8 @@ y1 = -0.021
 y2 = 1.5
 subdivy=1
 divy = 4
-x1=1.5328e-07
-x2=1.84945e-07
+x1=1.52536e-07
+x2=1.84201e-07
 divx=10
 subdivx=4
 node="ldcp ldyms[4] ldyms[5] ldyms[6] ldymsref"
@@ -61,8 +61,8 @@ y2 = 1.6
 divy = 3
 subdivy=0
 subdivx = 1
-x1=1.5328e-07
-x2=1.84945e-07  divx=10
+x1=1.52536e-07
+x2=1.84201e-07  divx=10
 node="
 ldwl[0] ldwl[1] ldwl[2] ldwl[3] 
 ldwl[4] ldwl[5] ldwl[6] ldwl[16] 
@@ -74,8 +74,8 @@ B 2 1840 -120 2890 -20 {flags=3
 y1 = -0.021
 y2 = 0.9
 divy = 1
-x1=1.5328e-07
-x2=1.84945e-07  divx=10
+x1=1.52536e-07
+x2=1.84201e-07  divx=10
 node="ldymsref"
 color=3 unitx=n subdivy=4
 }
@@ -83,11 +83,11 @@ B 2 1840 -880 2890 -420 {flags=3
 digital=1
 y1 = 0
 y2 = 1.6
-ypos1=0.0890868
-ypos2=2.14223
+ypos1=-0.0272427
+ypos2=2.11513
 divy = 1
-x1=2e-12
-x2=4.8e-07
+x1=1.52536e-07
+x2=1.84201e-07
 divx=12
 subdivx=4
 node="
@@ -103,7 +103,7 @@ LDL2X,ldl2x[3],ldl2x[2],ldl2x[1],ldl2x[0]
 LDL1X,ldl1x[15],ldl1x[14],ldl1x[13],ldl1x[12],ldl1x[11],ldl1x[10],ldl1x[9],ldl1x[8],ldl1x[7],ldl1x[6],ldl1x[5],ldl1x[4],ldl1x[3],ldl1x[2],ldl1x[1],ldl1x[0]
 LDY1,ldy1[3],ldy1[2],ldy1[1],ldy1[0]
 "
-color="3 15 4 15 3 15 4 3 4 15 4 15 4 15 4 15 4 15 4 15 4 15"
+color="18 15 4 15 18 15 4 18 4 15 4 15 4 15 4 15 4 15 4 15 4 15"
  unitx=n
  ypos1=-2.20115 ypos2=2.79884
 }
@@ -111,8 +111,8 @@ B 2 1840 -1280 2890 -1090 {flags=3
 y1 = -0.022
 y2 = 1.6
 divy = 4
-x1=1.5328e-07
-x2=1.84945e-07
+x1=1.52536e-07
+x2=1.84201e-07
 divx=8
 unitx=n
 node="xsa[0].ldqib xsa[5].ldqib xsa[0].ldsali xctrl.ldq_b"