diff --git a/src/readables/atarist.textpb b/src/readables/atarist.textpb
index f69d0992..c4afe5ad 100644
--- a/src/readables/atarist.textpb
+++ b/src/readables/atarist.textpb
@@ -6,7 +6,7 @@ input {
 
 output {
 	image {
-		filename: "atarist.img"
+		filename: "atarist.st"
 		img {}
 	}
 }
diff --git a/src/writables/atarist360.textpb b/src/writables/atarist360.textpb
index 624b3030..a420b524 100644
--- a/src/writables/atarist360.textpb
+++ b/src/writables/atarist360.textpb
@@ -1,6 +1,6 @@
 input {
 	image {
-		filename: "atarist360.img"
+		filename: "atarist360.st"
 		img {
 			tracks: 80
 			sides: 1
diff --git a/src/writables/atarist370.textpb b/src/writables/atarist370.textpb
index 11e8ee80..8c2fe8e7 100644
--- a/src/writables/atarist370.textpb
+++ b/src/writables/atarist370.textpb
@@ -1,6 +1,6 @@
 input {
 	image {
-		filename: "atarist370.img"
+		filename: "atarist370.st"
 		img {
 			tracks: 82
 			sides: 1
diff --git a/src/writables/atarist400.textpb b/src/writables/atarist400.textpb
index a6f537ae..b6921b5c 100644
--- a/src/writables/atarist400.textpb
+++ b/src/writables/atarist400.textpb
@@ -1,6 +1,6 @@
 input {
 	image {
-		filename: "atarist400.img"
+		filename: "atarist400.st"
 		img {
 			tracks: 80
 			sides: 1
diff --git a/src/writables/atarist410.textpb b/src/writables/atarist410.textpb
index 0d78049b..74137738 100644
--- a/src/writables/atarist410.textpb
+++ b/src/writables/atarist410.textpb
@@ -1,6 +1,6 @@
 input {
 	image {
-		filename: "atarist410.img"
+		filename: "atarist410.st"
 		img {
 			tracks: 82
 			sides: 1
diff --git a/src/writables/atarist720.textpb b/src/writables/atarist720.textpb
index 94f4a2b1..a0969472 100644
--- a/src/writables/atarist720.textpb
+++ b/src/writables/atarist720.textpb
@@ -1,6 +1,6 @@
 input {
 	image {
-		filename: "atarist720.img"
+		filename: "atarist720.st"
 		img {
 			tracks: 80
 			sides: 2
diff --git a/src/writables/atarist740.textpb b/src/writables/atarist740.textpb
index 44ac25f8..eccd085e 100644
--- a/src/writables/atarist740.textpb
+++ b/src/writables/atarist740.textpb
@@ -1,6 +1,6 @@
 input {
 	image {
-		filename: "atarist740.img"
+		filename: "atarist740.st"
 		img {
 			tracks: 82
 			sides: 2
diff --git a/src/writables/atarist800.textpb b/src/writables/atarist800.textpb
index ff05e29d..513aa023 100644
--- a/src/writables/atarist800.textpb
+++ b/src/writables/atarist800.textpb
@@ -1,6 +1,6 @@
 input {
 	image {
-		filename: "atarist800.img"
+		filename: "atarist800.st"
 		img {
 			tracks: 80
 			sides: 2
diff --git a/src/writables/atarist820.textpb b/src/writables/atarist820.textpb
index 4d2b0f07..ebccc99d 100644
--- a/src/writables/atarist820.textpb
+++ b/src/writables/atarist820.textpb
@@ -1,6 +1,6 @@
 input {
 	image {
-		filename: "atarist820.img"
+		filename: "atarist820.st"
 		img {
 			tracks: 82
 			sides: 2