diff --git a/package-lock.json b/package-lock.json
index 1d8c0078d..95e2c4c5c 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -20,7 +20,7 @@
         "@codemirror/view": "^6.26.3",
         "@emotion/react": "^11.11.4",
         "@emotion/styled": "^11.11.5",
-        "@microbit/microbit-connection": "^0.0.0-alpha.3",
+        "@microbit/microbit-connection": "^0.0.0-alpha.4",
         "@microbit/microbit-fs": "^0.9.2",
         "@sanity/block-content-to-react": "^3.0.0",
         "@sanity/image-url": "^1.0.1",
@@ -4020,9 +4020,9 @@
       }
     },
     "node_modules/@microbit/microbit-connection": {
-      "version": "0.0.0-alpha.3",
-      "resolved": "https://registry.npmjs.org/@microbit/microbit-connection/-/microbit-connection-0.0.0-alpha.3.tgz",
-      "integrity": "sha512-ZckWkYkQ78bCHcBSivht1HRQRtYes6is99ZCWgPggLsSFcZ84DFjlIA/QJnFSgBUT/k4Fn20ZJeGN7aVU0gy9w==",
+      "version": "0.0.0-alpha.4",
+      "resolved": "https://registry.npmjs.org/@microbit/microbit-connection/-/microbit-connection-0.0.0-alpha.4.tgz",
+      "integrity": "sha512-+ifTMR8NHhgTlCmkIN+CxT32w0c9v8gMbxI3a+K+5s89ZU7KinhxDyJ6QbRr8Vb3Qt5eJhh3hwa6VIHhTiXtrg==",
       "dependencies": {
         "@microbit/microbit-universal-hex": "^0.2.2",
         "@types/web-bluetooth": "^0.0.20",
diff --git a/package.json b/package.json
index 52a810b7a..2e29ce924 100644
--- a/package.json
+++ b/package.json
@@ -16,7 +16,7 @@
     "@codemirror/view": "^6.26.3",
     "@emotion/react": "^11.11.4",
     "@emotion/styled": "^11.11.5",
-    "@microbit/microbit-connection": "^0.0.0-alpha.3",
+    "@microbit/microbit-connection": "^0.0.0-alpha.4",
     "@microbit/microbit-fs": "^0.9.2",
     "@sanity/block-content-to-react": "^3.0.0",
     "@sanity/image-url": "^1.0.1",
diff --git a/src/fs/fs.test.ts b/src/fs/fs.test.ts
index 2505d9995..d903d80bb 100644
--- a/src/fs/fs.test.ts
+++ b/src/fs/fs.test.ts
@@ -9,7 +9,7 @@
 import * as fs from "fs";
 import * as fsp from "fs/promises";
 import { NullLogging } from "../deployment/default/logging";
-import { BoardId } from "@microbit/microbit-connection";
+import { MicroPythonSource } from "../micropython/micropython";
 import {
   diff,
   FileSystem,
@@ -20,7 +20,6 @@ import {
 } from "./fs";
 import { DefaultHost } from "./host";
 import { defaultInitialProject } from "./initial-project";
-import { MicroPythonSource } from "../micropython/micropython";
 
 const hexes = Promise.all([
   fs.readFileSync("src/micropython/microbit-micropython-v1.hex", {
@@ -39,7 +38,7 @@ const fsMicroPythonSource: MicroPythonSource = async () => {
       hex: v1,
     },
     {
-      boardId: 0x9003,
+      boardId: 0x9903,
       hex: v2,
     },
   ];
@@ -218,11 +217,12 @@ describe("Filesystem", () => {
     expect(typeof data).toEqual("string");
   });
 
-  it("creates board-specific data for flashing", async () => {
-    const boardId = BoardId.parse("9900");
-    const partial = await ufs.partialFlashData(boardId);
-    const full = await ufs.fullFlashData(boardId);
-    expect(partial.length).toBeLessThan(full.length);
+  it("creates board-specific data for flashing V1", async () => {
+    await ufs.asFlashDataSource()("V1");
+  });
+
+  it("creates board-specific data for flashing V2", async () => {
+    await ufs.asFlashDataSource()("V2");
   });
 
   it("gives useful stats", async () => {
diff --git a/src/fs/fs.ts b/src/fs/fs.ts
index b58925247..ba93f24e5 100644
--- a/src/fs/fs.ts
+++ b/src/fs/fs.ts
@@ -12,8 +12,8 @@ import sortBy from "lodash.sortby";
 import { lineNumFromUint8Array } from "../common/text-util";
 import {
   BoardId,
-  FlashDataSource,
   FlashDataError,
+  BoardVersion,
 } from "@microbit/microbit-connection";
 import { Logging } from "../logging/logging";
 import { MicroPythonSource } from "../micropython/micropython";
@@ -170,10 +170,7 @@ export const isNameLengthValid = (filename: string): boolean =>
  * or fire any events. This plays well with uncontrolled embeddings of
  * third-party text editors.
  */
-export class FileSystem
-  extends TypedEventTarget<EventMap>
-  implements FlashDataSource
-{
+export class FileSystem extends TypedEventTarget<EventMap> {
   private initializing: Promise<void> | undefined;
   private storage: FSStorage;
   private fileVersions: Map<string, number> = new Map();
@@ -463,22 +460,16 @@ export class FileSystem
     return this.storage.clearDirty();
   }
 
-  async fullFlashData(boardId: BoardId): Promise<string> {
-    try {
-      const fs = await this.initialize();
-      return fs.getIntelHex(boardId.normalize().id);
-    } catch (e: any) {
-      throw new FlashDataError(e.message);
-    }
-  }
-
-  async partialFlashData(boardId: BoardId): Promise<Uint8Array> {
-    try {
-      const fs = await this.initialize();
-      return fs.getIntelHexBytes(boardId.normalize().id);
-    } catch (e: any) {
-      throw new FlashDataError(e.message);
-    }
+  asFlashDataSource() {
+    return async (boardVersion: BoardVersion) => {
+      try {
+        const fs = await this.initialize();
+        const boardId = BoardId.forVersion(boardVersion).id;
+        return fs.getIntelHex(boardId);
+      } catch (e: any) {
+        throw new FlashDataError(e.message);
+      }
+    };
   }
 
   async files(): Promise<Record<string, Uint8Array>> {
diff --git a/src/project/project-actions.tsx b/src/project/project-actions.tsx
index 8dc7f5676..69a6b308a 100644
--- a/src/project/project-actions.tsx
+++ b/src/project/project-actions.tsx
@@ -140,11 +140,7 @@ export class ProjectActions {
       this.webusbNotSupportedError(finalFocusRef);
     } else {
       if (await this.showConnectHelp(forceConnectHelp, finalFocusRef)) {
-        return this.connectInternal(
-          { serial: userAction !== ConnectionAction.FLASH },
-          userAction,
-          finalFocusRef
-        );
+        return this.connectInternal({}, userAction, finalFocusRef);
       }
     }
   };
@@ -543,7 +539,10 @@ export class ProjectActions {
           progress: value,
         });
       };
-      await this.device.flash(this.fs, { partial: true, progress });
+      await this.device.flash(this.fs.asFlashDataSource(), {
+        partial: true,
+        progress,
+      });
     } catch (e) {
       if (e instanceof FlashDataError) {
         this.actionFeedback.expectedError({