diff --git a/ueforth/Makefile b/ueforth/Makefile
index 6a3a561..ddfbb68 100644
--- a/ueforth/Makefile
+++ b/ueforth/Makefile
@@ -7,11 +7,13 @@ WINDOWS = $(OUT)/windows
 ARDUINO = $(OUT)/arduino
 DEPLOY = $(OUT)/deploy
 
-CFLAGS_COMMON = -Wall -Werror \
-                -O2 \
+CFLAGS_COMMON = -O2 -I ./ -I $(OUT)
+
+CFLAGS_MINIMIZE = \
                 -s \
-                -ffreestanding \
+                -DUEFORTH_MINIMAL \
                 -fno-exceptions \
+                -ffreestanding \
                 -fno-stack-check \
                 -fno-stack-protector \
                 -fno-stack-protector \
@@ -19,9 +21,10 @@ CFLAGS_COMMON = -Wall -Werror \
                 -mno-stack-arg-probe \
                 -fno-ident -Wl,--build-id=none \
                 -ffunction-sections -fdata-sections \
-                -fmerge-all-constants \
-                -I ./ -I $(OUT)
+                -fmerge-all-constants
 CFLAGS = $(CFLAGS_COMMON) \
+         -Wall \
+         -Werror \
          -Wl,--gc-sections
 STRIP_ARGS = -S \
              --strip-unneeded \
@@ -32,39 +35,57 @@ STRIP_ARGS = -S \
              --remove-section=.note.ABI-tag
 LIBS=-ldl
 
-WIN_CFLAGS = $(CFLAGS_COMMON) -mwindows -nostdlib \
+WIN_CFLAGS = $(CFLAGS_COMMON) \
+             -I "c:/Program Files (x86)/Microsoft SDKs/Windows/v7.1A/Include" \
+             -I "c:/Program Files (x86)/Microsoft Visual Studio/2019/Community/VC/Tools/MSVC/14.28.29333/include" \
+             -I "c:/Program Files (x86)/Windows Kits/10/Include/10.0.19041.0/ucrt"
 
-WIN_LIBS = -lkernel32
+WIN_LFLAGS32 = /LIBPATH:"c:/Program Files (x86)/Microsoft SDKs/Windows/v7.1A/Lib" \
+               /LIBPATH:"c:/Program Files (x86)/Microsoft Visual Studio/2019/Community/VC/Tools/MSVC/14.28.29333/lib/x86" \
+               /LIBPATH:"c:/Program Files (x86)/Windows Kits/10/Lib/10.0.19041.0/ucrt/x86"
+
+WIN_LFLAGS64 = /LIBPATH:"c:/Program Files (x86)/Microsoft SDKs/Windows/v7.1A/Lib/x64" \
+               /LIBPATH:"c:/Program Files (x86)/Microsoft Visual Studio/2019/Community/VC/Tools/MSVC/14.28.29333/lib/x64" \
+               /LIBPATH:"c:/Program Files (x86)/Windows Kits/10/Lib/10.0.19041.0/ucrt/x64" \
 
 TARGETS = $(WEB)/terminal.html \
           $(WEB)/ueforth.js \
           $(POSIX)/ueforth \
           $(ARDUINO)/ueforth/ueforth.ino
 
+PROGFILES = /mnt/c/Program Files (x86)
+CL32 = "$(shell find "${PROGFILES}/Microsoft Visual Studio" -name cl.exe | grep /Hostx86/x86/ | head -n 1)"
+CL64 = "$(shell find "${PROGFILES}/Microsoft Visual Studio" -name cl.exe | grep /Hostx86/x64/ | head -n 1)"
+LINK32 = "$(shell find "${PROGFILES}/Microsoft Visual Studio" -name link.exe | grep /Hostx86/x86/ | head -n 1)"
+LINK64 = "$(shell find "${PROGFILES}/Microsoft Visual Studio" -name link.exe | grep /Hostx86/x64/ | head -n 1)"
+RC32 = "$(shell find "${PROGFILES}/Windows Kits" -name rc.exe | grep /x86/ | head -n 1)"
+RC64 = "$(shell find "${PROGFILES}/Windows Kits" -name rc.exe | grep /x64/ | head -n 1)"
+
 # Selectively enable windows if tools available
 DEPLOYABLE = 1
-ifneq (, $(shell which i686-w64-mingw32-windres))
-  ifneq (, $(shell which i686-w64-mingw32-gcc))
+ifneq (, $(CL32))
+  ifneq (, $(RC32))
     TARGETS += $(WINDOWS)/uEforth32.exe
   else
-    $(warning "Missing i686-w64-mingw32-gcc skipping 32-bit Windows.")
+    $(warning "Missing Visual Studio rc.exe skipping 32-bit Windows.")
     DEPLOYABLE := 0
   endif
 else
-  $(warning "Missing i686-w64-mingw32-windres skipping 32-bit Windows.")
+  $(warning "Missing Visual Studio cl.exe skipping 32-bit Windows.")
   DEPLOYABLE := 0
 endif
-ifneq (, $(shell which x86_64-w64-mingw32-windres))
-  ifneq (, $(shell which x86_64-w64-mingw32-gcc))
+ifneq (, $(CL64))
+  ifneq (, $(RC64))
     TARGETS += $(WINDOWS)/uEforth64.exe
   else
-    $(warning "Missing x86_64-w64-mingw32-gcc skipping 64-bit Windows.")
+    $(warning "Missing Visual Studio rc.exe skipping 64-bit Windows.")
     DEPLOYABLE := 0
   endif
 else
-  $(warning "Missing x86_64-w64-mingw32-windres skipping 64-bit Windows.")
+  $(warning "Missing Visual Studio cl.exe skipping 64-bit Windows.")
   DEPLOYABLE := 0
 endif
+
 # Decide if we can deploy.
 DEPLOY_TARGETS =
 ifeq (1, $(DEPLOYABLE))
@@ -145,11 +166,11 @@ ICON_SIZES = $(RES)/eforth256x256.png \
 $(RES)/eforth.ico: $(ICON_SIZES)
 	convert $^ $< $@
 
-$(RES)/ueforth_res32.o: windows/ueforth.rc $(RES)/eforth.ico
-	i686-w64-mingw32-windres $< $@
+$(RES)/ueforth_res32.res: windows/ueforth.rc $(RES)/eforth.ico
+	$(RC32) /fo $@ $<
 
-$(RES)/ueforth_res64.o: windows/ueforth.rc $(RES)/eforth.ico
-	x86_64-w64-mingw32-windres $< $@
+$(RES)/ueforth_res64.res: windows/ueforth.rc $(RES)/eforth.ico
+	$(RC64) /fo $@ $<
 
 # ---- WEB ----
 
@@ -175,6 +196,7 @@ $(POSIX):
 $(POSIX)/ueforth: \
     posix/posix_main.c \
     common/opcodes.h \
+    common/interp.h \
     common/core.h \
     $(GEN)/posix_boot.h | $(POSIX)
 	$(CC) $(CFLAGS) $< -o $@ $(LIBS)
@@ -185,23 +207,31 @@ $(POSIX)/ueforth: \
 $(WINDOWS):
 	mkdir -p $@
 
-$(WINDOWS)/uEforth32.exe: \
+$(WINDOWS)/uEforth32.obj: \
     windows/windows_main.c \
     common/opcodes.h \
     common/core.h \
-    $(GEN)/windows_boot.h \
-    $(RES)/ueforth_res32.o | $(WINDOWS)
-	i686-w64-mingw32-gcc \
-    $(WIN_CFLAGS) $< $(RES)/ueforth_res32.o -o $@ $(WIN_LIBS)
+    windows/windows_interp.h \
+    $(GEN)/windows_boot.h | $(WINDOWS)
+	$(CL32) /c /Fo$@ $(WIN_CFLAGS) $<
+
+$(WINDOWS)/uEforth32.exe: \
+    $(WINDOWS)/uEforth32.obj \
+    $(RES)/ueforth_res32.res | $(WINDOWS)
+	$(LINK32) /OUT:$@ $(WIN_LFLAGS32) $^
+
+$(WINDOWS)/uEforth64.obj: \
+    windows/windows_main.c \
+    common/opcodes.h \
+    common/core.h \
+    windows/windows_interp.h \
+    $(GEN)/windows_boot.h | $(WINDOWS)
+	$(CL64) /c /Fo$@ $(WIN_CFLAGS) $<
 
 $(WINDOWS)/uEforth64.exe: \
-    windows/windows_main.c \
-    common/opcodes.h \
-    common/core.h \
-    $(GEN)/windows_boot.h \
-    $(RES)/ueforth_res64.o | $(WINDOWS)
-	x86_64-w64-mingw32-gcc \
-    $(WIN_CFLAGS) $< $(RES)/ueforth_res64.o -o $@ $(WIN_LIBS)
+    $(WINDOWS)/uEforth64.obj \
+    $(RES)/ueforth_res64.res | $(WINDOWS)
+	$(LINK64) /OUT:$@ $(WIN_LFLAGS64) $^
 
 # ---- ARDUINO ----
 
@@ -213,6 +243,7 @@ $(ARDUINO)/ueforth/ueforth.ino: \
         arduino/arduino.template.ino \
         common/opcodes.h \
         common/core.h \
+        common/interp.h \
         $(GEN)/arduino_boot.h | $(ARDUINO)/ueforth
 	$^ >$@
 
diff --git a/ueforth/arduino/arduino.template.ino b/ueforth/arduino/arduino.template.ino
index dc100cc..a64775a 100644
--- a/ueforth/arduino/arduino.template.ino
+++ b/ueforth/arduino/arduino.template.ino
@@ -214,6 +214,7 @@ static char filename[PATH_MAX];
 static String string_value;
 
 {{core}}
+{{interp}}
 {{boot}}
 
 static IPAddress ToIP(cell_t ip) {
diff --git a/ueforth/arduino/fuse_ino.js b/ueforth/arduino/fuse_ino.js
index 6d41445..057abeb 100755
--- a/ueforth/arduino/fuse_ino.js
+++ b/ueforth/arduino/fuse_ino.js
@@ -5,10 +5,12 @@ var fs = require('fs');
 var code = fs.readFileSync(process.argv[2]).toString();
 var opcodes = fs.readFileSync(process.argv[3]).toString();
 var core = fs.readFileSync(process.argv[4]).toString();
-var boot = fs.readFileSync(process.argv[5]).toString();
+var interp = fs.readFileSync(process.argv[5]).toString();
+var boot = fs.readFileSync(process.argv[6]).toString();
 
 code = code.replace('{{opcodes}}', function() { return opcodes; });
 code = code.replace('{{boot}}', function() { return boot; });
 code = code.replace('{{core}}', function() { return core; });
+code = code.replace('{{interp}}', function() { return interp; });
 
 process.stdout.write(code);
diff --git a/ueforth/common/calling.h b/ueforth/common/calling.h
index b357029..03dc267 100644
--- a/ueforth/common/calling.h
+++ b/ueforth/common/calling.h
@@ -1,7 +1,7 @@
 #ifndef CALLTYPE
 # define CALLTYPE
 #endif
-typedef CALLTYPE cell_t (*call_t)();
+typedef cell_t (CALLTYPE *call_t)();
 
 #define CALLING_OPCODE_LIST \
   X("CALL0", OP_CALL0, tos = ((call_t) tos)()) \
diff --git a/ueforth/common/core.h b/ueforth/common/core.h
index a9ac434..83043cf 100644
--- a/ueforth/common/core.h
+++ b/ueforth/common/core.h
@@ -1,6 +1,5 @@
 #define PRINT_ERRORS 0
 
-#define NEXT w = *ip++; goto **(void **) w
 #define CELL_LEN(n) (((n) + sizeof(cell_t) - 1) / sizeof(cell_t))
 #define FIND(name) find(name, sizeof(name) - 1)
 #define LOWER(ch) ((ch) & 0x5F)
@@ -120,25 +119,7 @@ static cell_t *evaluate1(cell_t *sp) {
   return sp;
 }
 
-static void ueforth_run() {
-  if (!g_sys.ip) {
-#define X(name, op, code) create(name, sizeof(name) - 1, name[0] == ';', && OP_ ## op);
-    PLATFORM_OPCODE_LIST
-    OPCODE_LIST
-#undef X
-    return;
-  }
-  register cell_t *ip = g_sys.ip, *rp = g_sys.rp, *sp = g_sys.sp, tos, w;
-  DROP; NEXT;
-#define X(name, op, code) OP_ ## op: { code; } NEXT;
-  PLATFORM_OPCODE_LIST
-  OPCODE_LIST
-#undef X
-  OP_DOCOLON: ++rp; *rp = (cell_t) ip; ip = (cell_t *) (w + sizeof(cell_t)); NEXT;
-  OP_DOCREATE: DUP; tos = w + sizeof(cell_t) * 2; NEXT;
-  OP_DODOES: DUP; tos = w + sizeof(cell_t) * 2;
-             ++rp; *rp = (cell_t) ip; ip = (cell_t *) *(cell_t *) (w + sizeof(cell_t)); NEXT;
-}
+static void ueforth_run(void);
 
 static void ueforth(int argc, char *argv[], void *heap,
                     const char *src, cell_t src_len) {
diff --git a/ueforth/common/interp.h b/ueforth/common/interp.h
new file mode 100644
index 0000000..4f9a933
--- /dev/null
+++ b/ueforth/common/interp.h
@@ -0,0 +1,25 @@
+#define JMPW goto **(void **) w
+#define NEXT w = *ip++; JMPW
+#define ADDR_DOCOLON && OP_DOCOLON
+#define ADDR_DOCREATE && OP_DOCREATE
+#define ADDR_DODOES && OP_DODOES
+
+static void ueforth_run(void) {
+  if (!g_sys.ip) {
+#define X(name, op, code) create(name, sizeof(name) - 1, name[0] == ';', && OP_ ## op);
+    PLATFORM_OPCODE_LIST
+    OPCODE_LIST
+#undef X
+    return;
+  }
+  register cell_t *ip = g_sys.ip, *rp = g_sys.rp, *sp = g_sys.sp, tos, w;
+  DROP; NEXT;
+#define X(name, op, code) OP_ ## op: { code; } NEXT;
+  PLATFORM_OPCODE_LIST
+  OPCODE_LIST
+#undef X
+  OP_DOCOLON: ++rp; *rp = (cell_t) ip; ip = (cell_t *) (w + sizeof(cell_t)); NEXT;
+  OP_DOCREATE: DUP; tos = w + sizeof(cell_t) * 2; NEXT;
+  OP_DODOES: DUP; tos = w + sizeof(cell_t) * 2;
+             ++rp; *rp = (cell_t) ip; ip = (cell_t *) *(cell_t *) (w + sizeof(cell_t)); NEXT;
+}
diff --git a/ueforth/common/opcodes.h b/ueforth/common/opcodes.h
index 5ef9e54..0cc3acf 100644
--- a/ueforth/common/opcodes.h
+++ b/ueforth/common/opcodes.h
@@ -5,28 +5,29 @@
 
 typedef intptr_t cell_t;
 typedef uintptr_t ucell_t;
-#if __SIZEOF_POINTER__ == 8
-typedef __int128_t dcell_t;
-typedef __uint128_t udcell_t;
-#elif __SIZEOF_POINTER__ == 4
-typedef int64_t dcell_t;
-typedef uint64_t udcell_t;
-#else
-# error "unsupported cell size"
-#endif
 
 #define DUP *++sp = tos
 #define DROP tos = *sp--
 #define COMMA(n) *g_sys.heap++ = (n)
 #define IMMEDIATE() g_sys.last[-1] |= 1
-#define DOES(ip) *g_sys.last = (cell_t) && OP_DODOES; g_sys.last[1] = (cell_t) ip
-#ifndef SSMOD_FUNC
-#define SSMOD_FUNC dcell_t d = (dcell_t) *sp * (dcell_t) sp[-1]; \
-                   --sp; *sp = (cell_t) (((udcell_t) d) % tos); \
-                   tos = (cell_t) (d < 0 ? ~(~d / tos) : d / tos)
-#endif
+#define DOES(ip) *g_sys.last = (cell_t) ADDR_DODOES; g_sys.last[1] = (cell_t) ip
 #define PARK DUP; g_sys.ip = ip; g_sys.rp = rp; g_sys.sp = sp
 
+#ifndef SSMOD_FUNC
+# if __SIZEOF_POINTER__ == 8
+typedef __int128_t dcell_t;
+typedef __uint128_t udcell_t;
+# elif __SIZEOF_POINTER__ == 4 || defined(_M_IX86)
+typedef int64_t dcell_t;
+typedef uint64_t udcell_t;
+# else
+#  error "unsupported cell size"
+# endif
+# define SSMOD_FUNC dcell_t d = (dcell_t) *sp * (dcell_t) sp[-1]; \
+                    --sp; *sp = (cell_t) (((udcell_t) d) % tos); \
+                    tos = (cell_t) (d < 0 ? ~(~d / tos) : d / tos)
+#endif
+
 #define OPCODE_LIST \
   X("0=", ZEQUAL, tos = !tos ? -1 : 0) \
   X("0<", ZLESS, tos = (tos|0) < 0 ? -1 : 0) \
@@ -54,7 +55,7 @@ typedef uint64_t udcell_t;
   X(">R", TOR, *++rp = tos; DROP) \
   X("R>", FROMR, DUP; tos = *rp; --rp) \
   X("R@", RAT, DUP; tos = *rp) \
-  X("EXECUTE", EXECUTE, w = tos; DROP; goto **(void **) w) \
+  X("EXECUTE", EXECUTE, w = tos; DROP; JMPW) \
   X("BRANCH", BRANCH, ip = (cell_t *) *ip) \
   X("0BRANCH", ZBRANCH, if (!tos) ip = (cell_t *) *ip; else ++ip; DROP) \
   X("DONEXT", DONEXT, *rp = *rp - 1; \
@@ -67,17 +68,17 @@ typedef uint64_t udcell_t;
   X("S>NUMBER?", CONVERT, tos = convert((const char *) *sp, tos, sp); \
                           if (!tos) --sp) \
   X("CREATE", CREATE, DUP; DUP; tos = parse(32, sp); \
-                      create((const char *) *sp, tos, 0, && OP_DOCREATE); \
+                      create((const char *) *sp, tos, 0, ADDR_DOCREATE); \
                       COMMA(0); --sp; DROP) \
   X("DOES>", DOES, DOES(ip); ip = (cell_t *) *rp; --rp) \
   X("IMMEDIATE", IMMEDIATE, IMMEDIATE()) \
   X("'SYS", SYS, DUP; tos = (cell_t) &g_sys) \
   X("YIELD", YIELD, PARK; return) \
   X(":", COLON, DUP; DUP; tos = parse(32, sp); \
-                create((const char *) *sp, tos, 0, && OP_DOCOLON); \
+                create((const char *) *sp, tos, 0, ADDR_DOCOLON); \
                 g_sys.state = -1; --sp; DROP) \
   X("EVALUATE1", EVALUATE1, DUP; sp = evaluate1(sp); w = *sp--; DROP; \
-                            if (w) goto **(void **) w) \
+                            if (w) JMPW) \
   X("EXIT", EXIT, ip = (cell_t *) *rp--) \
   X(";", SEMICOLON, COMMA(g_sys.DOEXIT_XT); g_sys.state = 0) \
 
diff --git a/ueforth/posix/posix_main.c b/ueforth/posix/posix_main.c
index d60217e..674c5a0 100644
--- a/ueforth/posix/posix_main.c
+++ b/ueforth/posix/posix_main.c
@@ -12,6 +12,7 @@
   CALLING_OPCODE_LIST \
 
 #include "common/core.h"
+#include "common/interp.h"
 
 #include "gen/posix_boot.h"
 
diff --git a/ueforth/windows/windows_interp.h b/ueforth/windows/windows_interp.h
new file mode 100644
index 0000000..562a1e8
--- /dev/null
+++ b/ueforth/windows/windows_interp.h
@@ -0,0 +1,44 @@
+#define NEXT goto next
+#define JMPW goto work
+#define ADDR_DOCOLON ((void *) OP_DOCOLON)
+#define ADDR_DOCREATE ((void *) OP_DOCREATE)
+#define ADDR_DODOES ((void *) OP_DODOES)
+
+enum {
+  OP_DOCOLON = 0,
+  OP_DOCREATE,
+  OP_DODOES,
+#define X(name, op, code) OP_ ## op,
+  PLATFORM_OPCODE_LIST
+  OPCODE_LIST
+#undef X
+};
+
+static void ueforth_run(void) {
+  if (!g_sys.ip) {
+#define X(name, op, code) \
+    create(name, sizeof(name) - 1, name[0] == ';', (void *) OP_ ## op);
+    PLATFORM_OPCODE_LIST
+    OPCODE_LIST
+#undef X
+    return;
+  }
+  register cell_t *ip = g_sys.ip, *rp = g_sys.rp, *sp = g_sys.sp, tos, w;
+  DROP;
+  for (;;) {
+next:
+    w = *ip++;
+work:
+    switch (*(cell_t *) w & 0xff) {
+#define X(name, op, code) case OP_ ## op: { code; } NEXT;
+  PLATFORM_OPCODE_LIST
+  OPCODE_LIST
+#undef X
+      case OP_DOCOLON: ++rp; *rp = (cell_t) ip; ip = (cell_t *) (w + sizeof(cell_t)); NEXT;
+      case OP_DOCREATE: DUP; tos = w + sizeof(cell_t) * 2; NEXT;
+      case OP_DODOES: DUP; tos = w + sizeof(cell_t) * 2;
+                      ++rp; *rp = (cell_t) ip;
+                      ip = (cell_t *) *(cell_t *) (w + sizeof(cell_t)); NEXT;
+    }
+  }
+}
diff --git a/ueforth/windows/windows_main.c b/ueforth/windows/windows_main.c
index 086c8e7..201b0ce 100644
--- a/ueforth/windows/windows_main.c
+++ b/ueforth/windows/windows_main.c
@@ -1,12 +1,13 @@
+#define _USING_V110_SDK71_ 1
 #include "windows.h"
+#include <immintrin.h>
 
 #define CALLTYPE WINAPI
-
-# define SSMOD_FUNC \
-  w = tos; asm("imul %4\n\t" \
-      "idiv %2" \
-      : "=a" (tos), "=d" (sp[-1]) \
-      : "r" (w), "a" (sp[-1]), "d" (*sp)); --sp; if (*sp < 0) { *sp += w; --tos; }
+#if defined(_M_X64)
+# define SSMOD_FUNC --sp; cell_t b, a = _mul128(*sp, sp[1], &b); tos = _div128(b, a, tos, sp)
+#elif defined(_M_IX86)
+# define SSMOD_FUNC --sp; __int64 a = (__int64) *sp * (__int64) sp[1]; tos = _div64(a, tos, sp)
+#endif
 
 #include "common/opcodes.h"
 #include "common/calling.h"
@@ -22,13 +23,17 @@
   CALLING_OPCODE_LIST \
 
 #include "common/core.h"
+#include "windows/windows_interp.h"
 
 #include "gen/windows_boot.h"
 
+#ifdef UEFORTH_MINIMAL
 int WINAPI WinMainCRTStartup(void) {
+#else
+int WINAPI WinMain(HINSTANCE inst, HINSTANCE prev, LPSTR cmd, int show) {
+#endif
   void *heap = VirtualAlloc(
       NULL, HEAP_SIZE, MEM_RESERVE | MEM_COMMIT, PAGE_EXECUTE_READWRITE);
   ueforth(0, 0, heap, boot, sizeof(boot));
-  return 1;
 }