diff --git a/data/specs/01_rectangle b/data/specs/01_rectangle.js
similarity index 100%
rename from data/specs/01_rectangle
rename to data/specs/01_rectangle.js
diff --git a/data/specs/03_ideogram_barchart.js b/data/specs/03_ideogram_barchart.js
index 4355ecc..2225f44 100644
--- a/data/specs/03_ideogram_barchart.js
+++ b/data/specs/03_ideogram_barchart.js
@@ -6,9 +6,8 @@ var spec = {
   "tracks": [
     {
       "data": {
-        "type": "vector",
-        "url": "https://resgen.io/api/v1/tileset_info/?d=VLFaiSVjTjW6mkbjRjWREA",
-        "column": "position",
+        "type": "bigwig",
+        "url": "https://s3.amazonaws.com/gosling-lang.org/data/Astrocytes-insertions_bin100_RIPnorm.bw",
         "value": "peak"
       },
       "mark": "bar",
diff --git a/data/specs/04_circular_ideogram_barchart.js b/data/specs/04_circular_ideogram_barchart.js
index 913a874..c9d7aab 100644
--- a/data/specs/04_circular_ideogram_barchart.js
+++ b/data/specs/04_circular_ideogram_barchart.js
@@ -7,8 +7,8 @@ var spec = {
   "tracks": [
     {
       "data": {
-        "type": "vector",
-        "url": "https://resgen.io/api/v1/tileset_info/?d=VLFaiSVjTjW6mkbjRjWREA",
+        "type": "bigwig",
+        "url": "https://s3.amazonaws.com/gosling-lang.org/data/Astrocytes-insertions_bin100_RIPnorm.bw",
         "column": "position",
         "value": "peak"
       },
diff --git a/data/specs/05_gray_lines.js b/data/specs/05_gray_lines.js
index 08ff3b9..250beec 100644
--- a/data/specs/05_gray_lines.js
+++ b/data/specs/05_gray_lines.js
@@ -7,8 +7,8 @@ var spec = {
   "tracks": [
     {
       "data": {
-        "type": "vector",
-        "url": "https://resgen.io/api/v1/tileset_info/?d=VLFaiSVjTjW6mkbjRjWREA",
+        "type": "bigwig",
+        "url": "https://s3.amazonaws.com/gosling-lang.org/data/Astrocytes-insertions_bin100_RIPnorm.bw",
         "column": "position",
         "value": "peak"
       },
diff --git a/data/specs/06_circos.js b/data/specs/06_circos.js
index 2e74d52..dfdd7d7 100644
--- a/data/specs/06_circos.js
+++ b/data/specs/06_circos.js
@@ -8,8 +8,8 @@ var spec = {
   "tracks": [
     {
       "data": {
-        "type": "vector",
-        "url": "https://resgen.io/api/v1/tileset_info/?d=VLFaiSVjTjW6mkbjRjWREA",
+        "type": "bigwig",
+        "url": "https://s3.amazonaws.com/gosling-lang.org/data/Astrocytes-insertions_bin100_RIPnorm.bw",
         "column": "position",
         "value": "peak"
       },