diff --git a/ext/wasm/GNUmakefile b/ext/wasm/GNUmakefile
index ae9870054f..09b4479ba5 100644
--- a/ext/wasm/GNUmakefile
+++ b/ext/wasm/GNUmakefile
@@ -259,10 +259,11 @@ emcc.jsflags += -sMEMORY64=0
 # sqlite3.worker.js generated in conjunction with -sWASMFS).
 sqlite3.js := sqlite3.js
 sqlite3.wasm := sqlite3.wasm
-$(dir.api)/sqlite3-wasm.o: emcc.cflags += $(SQLITE_OPT)
-$(dir.api)/sqlite3-wasm.o: $(dir.top)/sqlite3.c
+sqlite3-wasm.o := $(dir.api)/sqlite3-wasm.o
+$(sqlite3-wasm.o): emcc.cflags += $(SQLITE_OPT)
+$(sqlite3-wasm.o): $(dir.top)/sqlite3.c
 $(dir.api)/wasm_util.o: emcc.cflags += $(SQLITE_OPT)
-sqlite3.wasm.c := $(dir.api)/sqlite3-wasm.c \
+sqlite3-wasm.c := $(dir.api)/sqlite3-wasm.c \
     $(dir.jacc)/jaccwabyt_test.c
 # ^^^ FIXME (how?): jaccwabyt_test.c is only needed for the test apps,
 # so we don't really want to include it in release builds. However, we
@@ -270,7 +271,7 @@ sqlite3.wasm.c := $(dir.api)/sqlite3-wasm.c \
 # elide that file in release builds. That component is critical to the
 # VFS bindings so needs to be tested along with the core APIs.
 ifneq (,$(filter -sWASMFS,$(emcc.jsflags)))
-  $(dir.api)/sqlite3-wasm.o: emcc.cflags+=-DSQLITE_WASM_OPFS
+  $(sqlite3-wasm.o): emcc.cflags+=-DSQLITE_WASM_OPFS
 endif
 define WASM_C_COMPILE
 $(1).o := $$(subst .c,.o,$(1))
@@ -279,7 +280,7 @@ $$($(1).o): $$(MAKEFILE) $(1)
 	$$(emcc.bin) $$(emcc_opt) $$(emcc.flags) $$(emcc.cflags) -c $(1) -o $$@
 CLEAN_FILES += $$($(1).o)
 endef
-$(foreach c,$(sqlite3.wasm.c),$(eval $(call WASM_C_COMPILE,$(c))))
+$(foreach c,$(sqlite3-wasm.c),$(eval $(call WASM_C_COMPILE,$(c))))
 $(sqlite3.js): 
 $(sqlite3.js): $(MAKEFILE) $(sqlite3.wasm.obj) \
     EXPORTED_FUNCTIONS.api \
@@ -298,7 +299,7 @@ wasm: $(sqlite3.js)
 ########################################################################
 
 ########################################################################
-# Bits for use with batch-runner.js...
+# batch-runner.js...
 dir.sql := sql
 speedtest1 := ../../speedtest1
 speedtest1.c := ../../test/speedtest1.c
@@ -317,24 +318,38 @@ clean-batch:
 # pieces each time is an unnecessary time sink.
 batch: batch-runner.list
 all: batch
+# end batch-runner.js
+########################################################################
+# speedtest1.js...
+emcc.speedtest1-flags := -g $(emcc_opt)
+ifneq (0,$(ENABLE_WASMFS))
+  emcc.speedtest1-flags += -pthread -sWASMFS -sPTHREAD_POOL_SIZE=2
+  emcc.speedtest1-flags += -DSQLITE_WASM_OPFS
+endif
+emcc.speedtest1-flags += -sINVOKE_RUN=0
+#emcc.speedtest1-flags += --no-entry
+emcc.speedtest1-flags += -flto
+emcc.speedtest1-flags += -sABORTING_MALLOC
+emcc.speedtest1-flags += -sINITIAL_MEMORY=128450560
+emcc.speedtest1-flags += -sSTRICT_JS
+emcc.speedtest1-flags += $(emcc.environment)
+emcc.speedtest1-flags += -sMODULARIZE
+emcc.speedtest1-flags += -sEXPORT_NAME=sqlite3Speedtest1InitModule
+emcc.speedtest1-flags += -Wno-limited-postlink-optimizations
+emcc.speedtest1-flags += -sEXPORTED_FUNCTIONS=_main,_malloc,_free,_sqlite3_wasm_vfs_unlink,_sqlite3_wasm_init_opfs
+emcc.speedtest1-flags += -sDYNAMIC_EXECUTION=0
+emcc.speedtest1-flags += --minify 0
 
 speedtest1.js := speedtest1.js
+speedtest1.wasm := $(subst .js,.wasm,$(speedtest1.js))
 $(speedtest1.js): emcc.cflags+=
-$(speedtest1.js): $(speedtest1.c) $(MAKEFILE)
-	$(emcc.bin) -g $(emcc_opt) \
-        -sINVOKE_RUN=0 \
-        --no-entry \
-        -sALLOW_TABLE_GROWTH \
-        -sABORTING_MALLOC \
-        -sINITIAL_MEMORY=128450560 \
-        -sSTRICT_JS \
-        -sENVIRONMENT=web \
-        -sMODULARIZE \
-        -sEXPORT_NAME=sqlite3Speedtest1InitModule \
-        -Wno-limited-postlink-optimizations \
-        -sEXPORTED_FUNCTIONS=_main,_malloc,_free \
-        -sDYNAMIC_EXECUTION=0 \
-        --minify 0 \
+# speedtest1 notes re. sqlite3-wasm.o vs sqlite3-wasm.c: building against
+# the latter (predictably) results in a slightly faster binary, but we're
+# close enough to the target speed requirements that the 500ms makes a
+# difference.
+$(speedtest1.js): $(speedtest1.c) $(sqlite3-wasm.c) $(MAKEFILE)
+	$(emcc.bin) \
+        $(emcc.speedtest1-flags) \
         -I. -I$(dir.top) \
         -DSQLITE_THREADSAFE=0 \
         -DSQLITE_TEMP_STORE=3 \
@@ -343,13 +358,16 @@ $(speedtest1.js): $(speedtest1.c) $(MAKEFILE)
         -DSQLITE_OMIT_SHARED_CACHE \
         '-DSQLITE_DEFAULT_UNIX_VFS="unix-none"' \
         -DSQLITE_SPEEDTEST1_WASM \
-        $(emcc_flags_wasmfs) \
-        -o $@ $(speedtest1.c) $(sqlite3.c) -lm
+        -o $@ $(speedtest1.c) $(sqlite3-wasm.c) -lm
+ifneq (,$(wasm-strip))
+	$(wasm-strip) $(speedtest1.wasm)
+endif
+	ls -la $@ $(speedtest1.wasm)
 
 speedtest1: $(speedtest1.js)
 all: $(speedtest1.js)
-CLEAN_FILES += $(speedtest1.js) $(subst .js,.wasm,$(speedtest1.js))
-
+CLEAN_FILES += $(speedtest1.js) $(speedtest1.wasm)
+# end speedtest1.js
 ########################################################################
 # fiddle_remote is the remote destination for the fiddle app. It
 # must be a [user@]HOST:/path for rsync.
diff --git a/ext/wasm/api/sqlite3-wasm.c b/ext/wasm/api/sqlite3-wasm.c
index 070282b8ee..cea6dffa1f 100644
--- a/ext/wasm/api/sqlite3-wasm.c
+++ b/ext/wasm/api/sqlite3-wasm.c
@@ -473,7 +473,7 @@ int sqlite3_wasm_init_opfs(const char *zMountPoint){
        hypothetically suffice for the transient wasm-based virtual
        filesystem we're currently running in. */
     const int rc = wasmfs_create_directory(zMountPoint, 0777, pOpfs);
-    emscripten_console_logf("OPFS mkdir rc=%d", rc);
+    emscripten_console_logf("OPFS mkdir(%s) rc=%d", zMountPoint, rc);
     if(rc) return SQLITE_IOERR;
   }
   return pOpfs ? 0 : SQLITE_NOMEM;
diff --git a/ext/wasm/common/whwasmutil.js b/ext/wasm/common/whwasmutil.js
index f72fba72c7..42f602d00d 100644
--- a/ext/wasm/common/whwasmutil.js
+++ b/ext/wasm/common/whwasmutil.js
@@ -1482,7 +1482,7 @@ self.WhWasmUtilInstaller = function(target){
     if(Array.isArray(arguments[3])) args = arguments[3];
     return target.xWrap(fname, resultType, argTypes||[]).apply(null, args||[]);
   };
-  
+
   return target;
 };
 
diff --git a/ext/wasm/speedtest1.html b/ext/wasm/speedtest1.html
index 526c05ac46..5e05feed26 100644
--- a/ext/wasm/speedtest1.html
+++ b/ext/wasm/speedtest1.html
@@ -31,10 +31,37 @@
     <script src="common/whwasmutil.js"></script>
     <script src="common/SqliteTestUtil.js"></script>
     <script src="speedtest1.js"></script>
-    <script>
-      (function(){
+    <script>(function(){
+        /**
+           If this environment contains OPFS, this function initializes it and
+           returns the name of the dir on which OPFS is mounted, else it returns
+           an empty string.
+        */
+        const opfsDir = function f(wasmUtil){
+          if(undefined !== f._) return f._;
+          const pdir = '/persistent';
+          if( !self.FileSystemHandle
+              || !self.FileSystemDirectoryHandle
+              || !self.FileSystemFileHandle){
+            return f._ = "";
+          }
+          try{
+            if(0===wasmUtil.xCallWrapped(
+              'sqlite3_wasm_init_opfs', 'i32', ['string'], pdir
+            )){
+              return f._ = pdir;
+            }else{
+              return f._ = "";
+            }
+          }catch(e){
+            // sqlite3_wasm_init_opfs() is not available
+            return f._ = "";
+          }
+        };
+        opfsDir._ = undefined;
+
         const eOut = document.querySelector('#test-output');
-        const logHtml2 = async function(cssClass,...args){
+        const log2 = async function(cssClass,...args){
           const ln = document.createElement('div');
           if(cssClass) ln.classList.add(cssClass);
           ln.append(document.createTextNode(args.join(' ')));
@@ -44,44 +71,53 @@
         const doHtmlOutput = false
         /* can't update DOM while speedtest is running unless we run
            speedtest in a worker thread. */;
-        const logHtml = (...args)=>{
+        const log = (...args)=>{
           console.log(...args);
-          if(doHtmlOutput) logHtml2('', ...args);
+          if(doHtmlOutput) log2('', ...args);
         };
         const logErr = function(...args){
           console.error(...args);
-          if(doHtmlOutput) this.logHtml2('error', ...args);
+          if(doHtmlOutput) log2('error', ...args);
         };
 
         const runTests = function(EmscriptenModule){
-          console.log("Module inited.");
+          console.log("Module inited.",EmscriptenModule);
           const wasm = {
             exports: EmscriptenModule.asm,
             alloc: (n)=>EmscriptenModule._malloc(n),
-            dealloc: (m)=>EmscriptenModule._free(m)
+            dealloc: (m)=>EmscriptenModule._free(m),
+            memory: EmscriptenModule.asm.memory || EmscriptenModule.wasmMemory
           };
-          //console.debug('Emscripten Module =',EmscriptenModule);
           //console.debug('wasm =',wasm);
           self.WhWasmUtilInstaller(wasm);
+          const unlink = wasm.xWrap("sqlite3_wasm_vfs_unlink", "int", ["string"]);
+          const pDir = opfsDir(wasm);
+          if(pDir){
+            console.warn("Persistent storage:",pDir);
+          }
           const scope = wasm.scopedAllocPush();
+          const dbFile = 0 ? "" : pDir+"/speedtest1.db";
           try{
-            const maxArgc = 12;
-            const aArgs = [
+            const argv = [
               // TODO: accept flags via URL arguments and/or a
               // UI control. A multi-SELECT element should do
               // nicely.
               "speedtest1",
-              "--memdb",
-              "--stats"
+              "--singlethread",
+              //"--stats",
+              "--memdb", // note that memdb trumps the filename arg
+              dbFile
             ];
-            wasm.xCall('__main_argc_argv', aArgs.length,
-                       wasm.scopedAllocMainArgv(aArgs));
+            console.log("argv =",argv);
+            wasm.xCall('__main_argc_argv', argv.length,
+                       wasm.scopedAllocMainArgv(argv));
           }finally{
             wasm.scopedAllocPop(scope);
+            if(pDir) unlink(dbFile);
           }
         };
 
-        self.sqlite3TestModule.print = logHtml;
+        self.sqlite3TestModule.print = log;
         self.sqlite3TestModule.printErr = logErr;
         sqlite3Speedtest1InitModule(self.sqlite3TestModule).then(function(M){
           setTimeout(()=>runTests(M), 100);
diff --git a/manifest b/manifest
index 91cc5e9d1c..22d4c0358d 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Initial\sbuild\sof\sspeedtest1.wasm\sand\sspeedtest1.html\swith\swhich\sto\srun\sit.
-D 2022-09-06T16:47:43.072
+C Get\sspeedtest1.js\sworking\swith\sWASMFS/OPFS.
+D 2022-09-06T20:17:15.425
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -474,7 +474,7 @@ F ext/userauth/user-auth.txt e6641021a9210364665fe625d067617d03f27b04
 F ext/userauth/userauth.c 7f00cded7dcaa5d47f54539b290a43d2e59f4b1eb5f447545fa865f002fc80cb
 F ext/wasm/EXPORTED_FUNCTIONS.fiddle db7a4602f043cf4a5e4135be3609a487f9f1c83f05778bfbdf93766be4541b96
 F ext/wasm/EXPORTED_RUNTIME_METHODS.fiddle a004bd5eeeda6d3b28d16779b7f1a80305bfe009dfc7f0721b042967f0d39d02
-F ext/wasm/GNUmakefile 445b81c44804f029bcc938aa777ca3fe450a0061a586a21be411362575c7cf61
+F ext/wasm/GNUmakefile 2333e782a412c56438e9c08b56b8e26d402d70067760925e6900df5cb4165b66
 F ext/wasm/README.md e1ee1e7c321c6a250bf78a84ca6f5882890a237a450ba5a0649c7a8399194c52
 F ext/wasm/api/EXPORTED_FUNCTIONS.sqlite3-api 77ef4bcf37e362b9ad61f9c175dfc0f1b3e571563fb311b96581cf422ee6a8ec
 F ext/wasm/api/EXPORTED_RUNTIME_METHODS.sqlite3-api 1ec3c73e7d66e95529c3c64ac3de2470b0e9e7fbf7a5b41261c367cf4f1b7287
@@ -488,13 +488,13 @@ F ext/wasm/api/sqlite3-api-opfs.js 011799db398157cbd254264b6ebae00d7234b93d0e9e8
 F ext/wasm/api/sqlite3-api-prologue.js 2d5c5d3355f55eefe51922cec5bfedbec0f8300db98a17685ab7a34a03953c7a
 F ext/wasm/api/sqlite3-api-worker1.js 73579555563b789785ae83724014eaf31811073aad9be6596c8336ffb51edd71
 F ext/wasm/api/sqlite3-wasi.h 25356084cfe0d40458a902afb465df8c21fc4152c1d0a59b563a3fba59a068f9
-F ext/wasm/api/sqlite3-wasm.c 0d81282eaeff2a6e9fc5c28a388c5c5b45cf25a9393992fa511ac009b27df982
+F ext/wasm/api/sqlite3-wasm.c 19c3797edc35821e362a8b60ce45d1adfe6d24fca7cd1f55f89d2086ef33870e
 F ext/wasm/batch-runner.html 2d44d99a556c46f586d3319003dd281dd0eb6a13eeadde3eab05ba81eec9ff8a
 F ext/wasm/batch-runner.js a727cbbffe63fd17fb5a590dc679f0b13bd51880e8f84b461d7df246417689e8
 F ext/wasm/common/SqliteTestUtil.js 7a543e238c2ebda922c85076abda017d0480944fdfee576692a0c3a580319ebd
 F ext/wasm/common/emscripten.css 3d253a6fdb8983a2ac983855bfbdd4b6fa1ff267c28d69513dd6ef1f289ada3f
 F ext/wasm/common/testing.css 572cf1ffae0b6eb7ca63684d3392bf350217a07b90e7a896e4fa850700c989b0
-F ext/wasm/common/whwasmutil.js ed10ab537b800e1f8fac9d5ecec00908f4d4b0e1a270de196e43782600ae59f7
+F ext/wasm/common/whwasmutil.js f7282ef36c9625330d4e6e82d1beec6678cd101e95e7108cd85db587a788c145
 F ext/wasm/demo-oo1.html 75646855b38405d82781246fd08c852a2b3bee05dd9f0fe10ab655a8cffb79aa
 F ext/wasm/demo-oo1.js aad38cb90b6fa7fd4d1184e759b25056fb4ed45c4957c458896354281259515f
 F ext/wasm/fiddle/emscripten.css 3d253a6fdb8983a2ac983855bfbdd4b6fa1ff267c28d69513dd6ef1f289ada3f
@@ -510,7 +510,7 @@ F ext/wasm/scratchpad-opfs-main.js 69e960e9161f6412fd0c30f355d4112f1894d6609eb43
 F ext/wasm/scratchpad-opfs-worker.html 66c1d15d678f3bd306373d76b61c6c8aef988f61f4a8dd40185d452f9c6d2bf5
 F ext/wasm/scratchpad-opfs-worker.js 3ec2868c669713145c76eb5877c64a1b20741f741817b87c907a154b676283a9
 F ext/wasm/scratchpad-opfs-worker2.js 5f2237427ac537b8580b1c659ff14ad2621d1694043eaaf41ae18dbfef2e48c0
-F ext/wasm/speedtest1.html e5b6ca8d09e15ab77fcec95ab30a330cc5376795f3d3b7cc05b9377b08824071
+F ext/wasm/speedtest1.html a1204f5cbbd592baa191535dc7eaa2d875f661aefb2a70a4631df0a925e19f4b
 F ext/wasm/split-speedtest1-script.sh a3e271938d4d14ee49105eb05567c6a69ba4c1f1293583ad5af0cd3a3779e205 x
 F ext/wasm/sql/000-mandelbrot.sql 775337a4b80938ac8146aedf88808282f04d02d983d82675bd63d9c2d97a15f0
 F ext/wasm/sql/001-sudoku.sql 35b7cb7239ba5d5f193bc05ec379bcf66891bce6f2a5b3879f2f78d0917299b5
@@ -2016,8 +2016,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 09796cc2bfce7bc4ce11db9673d20737259e9928f0484660cba3a9751f7d01c5
-R 98ebaeee264c8d9d604307fc8843d5b6
+P 4441535e3e54dc1881f700fa3878964eb8554a6790fd6aa32945f7cc104a8467
+R 63d4e2043bd53d54be9ba5bac375f852
 U stephan
-Z 0a749029dbb2383547531131a6904c9b
+Z 29ed13e3400f211a842f97710dcb5fd5
 # Remove this line to create a well-formed Fossil manifest.
diff --git a/manifest.uuid b/manifest.uuid
index 11b9ffd031..6d532fae16 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-4441535e3e54dc1881f700fa3878964eb8554a6790fd6aa32945f7cc104a8467
\ No newline at end of file
+40e60f570d4f489d58d12e27c1c067b41d6c5a5e374c5fce0baa8881ef183216
\ No newline at end of file