diff --git a/libs/base/shims.d.ts b/libs/base/shims.d.ts
index ece391a3..d54c32f0 100644
--- a/libs/base/shims.d.ts
+++ b/libs/base/shims.d.ts
@@ -10,6 +10,12 @@ declare interface Buffer {
     //% shim=BufferMethods::getUint8
     getUint8(off: int32): int32;
 
+    /**
+     * Returns false when the buffer can be written to.
+     */
+    //% shim=BufferMethods::isReadOnly
+    isReadOnly(): boolean;
+
     /**
      * Writes an unsigned byte at a particular location
      */
diff --git a/libs/core/shims.d.ts b/libs/core/shims.d.ts
index 23fccb50..de88d881 100644
--- a/libs/core/shims.d.ts
+++ b/libs/core/shims.d.ts
@@ -65,6 +65,13 @@ declare namespace control {
     //% help=control/allocate-notify-event shim=control::allocateNotifyEvent
     function allocateNotifyEvent(): int32;
 
+    /**
+     * Determine the version of system software currently running.
+     */
+    //% blockId="control_device_dal_version" block="device dal version"
+    //% help=control/device-dal-version shim=control::deviceDalVersion
+    function deviceDalVersion(): string;
+
     /** Write data to DMESG debugging buffer. */
     //% shim=control::dmesg
     function dmesg(s: string): void;