diff --git a/apple/applemmu.cpp b/apple/applemmu.cpp
index 2ba4005..84216e2 100644
--- a/apple/applemmu.cpp
+++ b/apple/applemmu.cpp
@@ -12,10 +12,13 @@
 #include "physicalspeaker.h"
 #include "cpu.h"
 
+#include "serialize.h"
+
 #include "globals.h"
 
 #ifdef TEENSYDUINO
 #include "teensy-clock.h"
+#include "iocompat.h"
 #else
 #include "nix-clock.h"
 #endif
@@ -166,24 +169,23 @@ AppleMMU::~AppleMMU()
 
 bool AppleMMU::Serialize(int8_t fd)
 {
-  uint8_t buf[13] = { MMUMAGIC,
-		      (uint8_t)((switches >> 8) & 0xFF),
-		      (uint8_t)((switches     ) & 0xFF),
-		      auxRamRead ? 1 : 0,
-		      auxRamWrite ? 1 : 0,
-		      bank2 ? 1 : 0,
-		      readbsr ? 1 : 0,
-		      writebsr ? 1 : 0,
-		      altzp ? 1 : 0,
-		      intcxrom ? 1 : 0,
-		      slot3rom ? 1 : 0,
-		      slotLatch,
-		      preWriteFlag ? 1 : 0 };
-  if (g_filemanager->write(fd, buf, 13) != 13)
-    return false;
+  serializeMagic(MMUMAGIC);
+  serialize16(switches);
+  serialize8(auxRamRead ? 1 : 0);
+  serialize8(auxRamWrite ? 1 : 0);
+  serialize8(bank2 ? 1 : 0);
+  serialize8(readbsr ? 1 : 0);
+  serialize8(writebsr ? 1 : 0);
+  serialize8(altzp ? 1 : 0);
+  serialize8(intcxrom ? 1 : 0);
+  serialize8(slot3rom ? 1 : 0);
+  serialize8(slotLatch);
+  serialize8(preWriteFlag ? 1 : 0);
   
-  if (!g_ram.Serialize(fd))
-    return false;
+  if (!g_ram.Serialize(fd)) {
+    printf("Failed to serialize RAM\n");
+    goto err;
+  }
 
   // readPages & writePages don't need suspending, but we will need to
   // recalculate after resume
@@ -191,47 +193,42 @@ bool AppleMMU::Serialize(int8_t fd)
   // Not suspending/resuming slots b/c they're a fixed configuration
   // in this project. Should probably checksum them though. FIXME.
 
-  if (g_filemanager->write(fd, buf, 1) != 1)
-    return false;
-  
+  serializeMagic(MMUMAGIC);
   return true;
+
+ err:
+  return false;
 }
 
 bool AppleMMU::Deserialize(int8_t fd)
 {
-  uint8_t buf[13];
+  deserializeMagic(MMUMAGIC);
 
-  if (g_filemanager->read(fd, buf, 13) != 13)
-    return false;
+  deserialize16(switches);
+  serialize8(auxRamRead);
+  serialize8(auxRamWrite);
+  serialize8(bank2);
+  serialize8(readbsr);
+  serialize8(writebsr);
+  serialize8(altzp);
+  serialize8(intcxrom);
+  serialize8(slot3rom);
+  serialize8(slotLatch);
+  serialize8(preWriteFlag);
 
-  if (buf[0] != MMUMAGIC)
-    return false;
-
-  switches = (buf[1] << 8) | buf[2];
-  auxRamRead = buf[3];
-  auxRamWrite = buf[4];
-  bank2 = buf[5];
-  readbsr = buf[6];
-  writebsr = buf[7];
-  altzp = buf[8];
-  intcxrom = buf[9];
-  slot3rom = buf[10];
-  slotLatch = buf[11];
-  preWriteFlag = buf[12];
-  
   if (!g_ram.Deserialize(fd)) {
-    return false;
+    goto err;
   }
 
-  if (g_filemanager->read(fd, buf, 1) != 1)
-    return false;
-  if (buf[0] != MMUMAGIC)
-    return false;
+  deserializeMagic(MMUMAGIC);
 
   // Reset readPages[] and writePages[] and the display
   resetDisplay();
 
   return true;
+
+ err:
+  return false;
 }
 
 
diff --git a/apple/applevm.cpp b/apple/applevm.cpp
index b0c822c..3fc0d2c 100644
--- a/apple/applevm.cpp
+++ b/apple/applevm.cpp
@@ -6,10 +6,13 @@
 #include "applekeyboard.h"
 #include "physicalkeyboard.h"
 
+#include "serialize.h"
+
 #include "globals.h"
 
 #ifdef TEENSYDUINO
 #include "teensy-println.h"
+#include "iocompat.h"
 #endif
 
 #include <errno.h>
@@ -43,83 +46,75 @@ AppleVM::~AppleVM()
   delete parallel;
 }
 
-void AppleVM::Suspend(const char *fn)
+bool AppleVM::Suspend(const char *fn)
 {
   /* Open a new suspend file via the file manager; tell all our
      objects to serialize in to it; close the file */
 
-  int8_t fh = g_filemanager->openFile(fn);
-  if (fh == -1) {
+  int8_t fd = g_filemanager->openFile(fn);
+  if (fd == -1) {
     // Unable to open; skip suspend
-    return;
+    printf("failed to open suspend file\n");
+    return false;
   }
 
   /* Header */
-  if (g_filemanager->write(fh, suspendHdr, strlen(suspendHdr)) != strlen(suspendHdr))
-    return;
+  serializeString(suspendHdr);
 
   /* Tell all of the peripherals to suspend */
-  if (g_cpu->Serialize(fh) &&
-      disk6->Serialize(fh) &&
-      hd32->Serialize(fh)
+  if (g_cpu->Serialize(fd) &&
+      disk6->Serialize(fd) &&
+      hd32->Serialize(fd)
       ) {
-#ifdef TEENSYDUINO
-    println("All serialized successfully");
-#else
     printf("All serialized successfully\n");
-#endif
   }
 
-  g_filemanager->closeFile(fh);
+  g_filemanager->closeFile(fd);
+  return true;
+  
+ err:
+  g_filemanager->closeFile(fd);
+  return false;
 }
 
-void AppleVM::Resume(const char *fn)
+bool AppleVM::Resume(const char *fn)
 {
   /* Open the given suspend file via the file manager; tell all our
      objects to deserialize from it; close the file */
 
-  int8_t fh = g_filemanager->openFile(fn);
-  if (fh == -1) {
+  int8_t fd = g_filemanager->openFile(fn);
+  if (fd == -1) {
     // Unable to open; skip resume
-#ifdef TEENSYDUINO
-    print("Unable to open resume file ");
-    println(fn);
-#else
-    printf("Unable to open resume file\n");
-#endif
-    g_filemanager->closeFile(fh);
-    return;
+    printf("Unable to open resume file '%s'\n", fn);
+    goto err;
   }
 
   /* Header */
-  uint8_t c;
-  for (int i=0; i<strlen(suspendHdr); i++) {
-    if (g_filemanager->read(fh, &c, 1) != 1 ||
-	c != suspendHdr[i]) {
-      /* Failed to read correct header; abort */
-      g_filemanager->closeFile(fh);
-      return;
-    }
+  deserializeString(debugBuf);
+  if (strcmp(debugBuf, suspendHdr)) {
+    printf("Bad file header while resuming\n");
+    goto err;
   }
 
   /* Tell all of the peripherals to resume */
-  if (g_cpu->Deserialize(fh) &&
-      disk6->Deserialize(fh) &&
-      hd32->Deserialize(fh)
+  if (g_cpu->Deserialize(fd) &&
+      disk6->Deserialize(fd) &&
+      hd32->Deserialize(fd)
       ) {
-#ifdef TEENSYDUINO
-    println("Deserialization successful");
-#else
     printf("All deserialized successfully\n");
-#endif
   } else {
-#ifndef TEENSYDUINO
     printf("Deserialization failed\n");
+#ifndef TEENSYDUINO
     exit(1);
 #endif
+    goto err;
   }
 
-  g_filemanager->closeFile(fh);
+  g_filemanager->closeFile(fd);
+  return true;
+ err:
+  g_filemanager->closeFile(fd);
+  return false;
 }
 
 // fixme: make member vars
diff --git a/apple/applevm.h b/apple/applevm.h
index 65e02f4..57759b1 100644
--- a/apple/applevm.h
+++ b/apple/applevm.h
@@ -15,8 +15,8 @@ class AppleVM : public VM {
   AppleVM();
   virtual ~AppleVM();
 
-  void Suspend(const char *fn);
-  void Resume(const char *fn);
+  bool Suspend(const char *fn);
+  bool Resume(const char *fn);
 
   void cpuMaintenance(int64_t cycles);
 
diff --git a/apple/diskii.cpp b/apple/diskii.cpp
index 16177d1..42f9288 100644
--- a/apple/diskii.cpp
+++ b/apple/diskii.cpp
@@ -3,6 +3,7 @@
 #ifdef TEENSYDUINO
 #include <Arduino.h>
 #include "teensy-println.h"
+#include "iocompat.h"
 #else
 #include <unistd.h>
 #include <fcntl.h>
@@ -16,6 +17,8 @@
 #include "globals.h"
 #include "appleui.h"
 
+#include "serialize.h"
+
 #include "diskii-rom.h"
 
 #define DISKIIMAGIC 0xAA
@@ -57,171 +60,101 @@ DiskII::~DiskII()
 
 bool DiskII::Serialize(int8_t fd)
 {
-  uint8_t buf[27] = { DISKIIMAGIC,
-		      readWriteLatch,
-		      sequencer,
-		      dataRegister,
-		      writeMode,
-		      writeProt,
-		      selectedDisk };
+  serializeMagic(DISKIIMAGIC);
+  serialize8(readWriteLatch);
+  serialize8(sequencer);
+  serialize8(dataRegister);
+  serialize8(writeMode);
+  serialize8(writeProt);
+  serialize8(selectedDisk);
   
-  if (g_filemanager->write(fd, buf, 7) != 7) {
-    return false;
-  }
-
   for (int i=0; i<2; i++) {
-    uint8_t ptr = 0;
-    buf[ptr++] = curHalfTrack[i];
-    buf[ptr++] = curWozTrack[i];
-    buf[ptr++] = curPhase[i];
-    buf[ptr++] = ((driveSpinupCycles[i] >> 56) & 0xFF);
-    buf[ptr++] = ((driveSpinupCycles[i] >> 48) & 0xFF);
-    buf[ptr++] = ((driveSpinupCycles[i] >> 40) & 0xFF);
-    buf[ptr++] = ((driveSpinupCycles[i] >> 32) & 0xFF);
-    buf[ptr++] = ((driveSpinupCycles[i] >> 24) & 0xFF);
-    buf[ptr++] = ((driveSpinupCycles[i] >> 16) & 0xFF);
-    buf[ptr++] = ((driveSpinupCycles[i] >>  8) & 0xFF);
-    buf[ptr++] = ((driveSpinupCycles[i]      ) & 0xFF);
-    buf[ptr++] = ((deliveredDiskBits[i] >> 56) & 0xFF);
-    buf[ptr++] = ((deliveredDiskBits[i] >> 48) & 0xFF);
-    buf[ptr++] = ((deliveredDiskBits[i] >> 40) & 0xFF);
-    buf[ptr++] = ((deliveredDiskBits[i] >> 32) & 0xFF);
-    buf[ptr++] = ((deliveredDiskBits[i] >> 24) & 0xFF);
-    buf[ptr++] = ((deliveredDiskBits[i] >> 16) & 0xFF);
-    buf[ptr++] = ((deliveredDiskBits[i] >>  8) & 0xFF);
-    buf[ptr++] = ((deliveredDiskBits[i]      ) & 0xFF);
-    buf[ptr++] = (diskIsSpinningUntil[i] >> 56) & 0xFF;
-    buf[ptr++] = (diskIsSpinningUntil[i] >> 48) & 0xFF;
-    buf[ptr++] = (diskIsSpinningUntil[i] >> 40) & 0xFF;
-    buf[ptr++] = (diskIsSpinningUntil[i] >> 32) & 0xFF;
-    buf[ptr++] = (diskIsSpinningUntil[i] >> 24) & 0xFF;
-    buf[ptr++] = (diskIsSpinningUntil[i] >> 16) & 0xFF;
-    buf[ptr++] = (diskIsSpinningUntil[i] >>  8) & 0xFF;
-    buf[ptr++] = (diskIsSpinningUntil[i]      ) & 0xFF;
-    // Safety check: keeping the hard-coded 27 and comparing against ptr.
-    // If we change the 27, also need to change the size of buf[] above
-    if (g_filemanager->write(fd, buf, 27) != ptr) {
-      return false;
-    }
+    serialize8(curHalfTrack[i]);
+    serialize8(curWozTrack[i]);
+    serialize8(curPhase[i]);
+    serialize64(driveSpinupCycles[i]);
+    serialize64(deliveredDiskBits[i]);
+    serialize64(diskIsSpinningUntil[i]);
     
     if (disk[i]) {
       // Make sure we have flushed the disk images
       disk[i]->flush();
       flushAt[i] = 0; // and there's no need to re-flush them now
 
-      buf[0] = 1;
-      if (g_filemanager->write(fd, buf, 1) != 1)
-	return false;
+      serialize8(1);
 
       // FIXME: this ONLY works for builds using the filemanager to read
       // the disk image, so it's broken until we port Woz to do that!
       const char *fn = disk[i]->diskName();
-      if (g_filemanager->write(fd, fn, strlen(fn)+1) != strlen(fn)+1)  // include null terminator
-	return false;
+      serializeString(fn);
       if (!disk[i]->Serialize(fd))
-	return false;
+	goto err;
     } else {
-      buf[0] = 0;
-      if (g_filemanager->write(fd, buf, 0) != 1)
-	return false;
+      serialize8(0);
     }
   }
 
-  buf[0] = DISKIIMAGIC;
-  if (g_filemanager->write(fd, buf, 1) != 1)
-    return false;
+  serializeMagic(DISKIIMAGIC);
 
   return true;
+ err:
+  return false;
 }
 
 bool DiskII::Deserialize(int8_t fd)
 {
-  uint8_t buf[MAXPATH];
-  if (g_filemanager->read(fd, buf, 7) != 7)
-    return false;
-  if (buf[0] != DISKIIMAGIC)
-    return false;
+  deserializeMagic(DISKIIMAGIC);
 
-  readWriteLatch = buf[1];
-  sequencer = buf[2];
-  dataRegister = buf[3];
-  writeMode = buf[4];
-  writeProt = buf[5];
-  selectedDisk = buf[6];
+  deserialize8(readWriteLatch);
+  deserialize8(sequencer);
+  deserialize8(dataRegister);
+  deserialize8(writeMode);
+  deserialize8(writeProt);
+  deserialize8(selectedDisk);
 
   for (int i=0; i<2; i++) {
-    uint8_t ptr = 0;
-    if (g_filemanager->read(fd, buf, 27) != 27)
-      return false;
+    deserialize8(curHalfTrack[i]);
+    deserialize8(curWozTrack[i]);
+    deserialize8(curPhase[i]);
 
-    curHalfTrack[i] = buf[ptr++];
-    curWozTrack[i] = buf[ptr++];
-    curPhase[i] = buf[ptr++];
+    deserialize64(driveSpinupCycles[i]);
+    deserialize64(deliveredDiskBits[i]);
+    deserialize64(diskIsSpinningUntil[i]);
 
-    driveSpinupCycles[i] = buf[ptr++];
-    driveSpinupCycles[i] <<= 8; driveSpinupCycles[i] |= buf[ptr++];
-    driveSpinupCycles[i] <<= 8; driveSpinupCycles[i] |= buf[ptr++];
-    driveSpinupCycles[i] <<= 8; driveSpinupCycles[i] |= buf[ptr++];
-    driveSpinupCycles[i] <<= 8; driveSpinupCycles[i] |= buf[ptr++];
-    driveSpinupCycles[i] <<= 8; driveSpinupCycles[i] |= buf[ptr++];
-    driveSpinupCycles[i] <<= 8; driveSpinupCycles[i] |= buf[ptr++];
-    driveSpinupCycles[i] <<= 8; driveSpinupCycles[i] |= buf[ptr++];
-
-    deliveredDiskBits[i] = buf[ptr++];
-    deliveredDiskBits[i] <<= 8; deliveredDiskBits[i] |= buf[ptr++];
-    deliveredDiskBits[i] <<= 8; deliveredDiskBits[i] |= buf[ptr++];
-    deliveredDiskBits[i] <<= 8; deliveredDiskBits[i] |= buf[ptr++];
-    deliveredDiskBits[i] <<= 8; deliveredDiskBits[i] |= buf[ptr++];
-    deliveredDiskBits[i] <<= 8; deliveredDiskBits[i] |= buf[ptr++];
-    deliveredDiskBits[i] <<= 8; deliveredDiskBits[i] |= buf[ptr++];
-    deliveredDiskBits[i] <<= 8; deliveredDiskBits[i] |= buf[ptr++];
-
-    diskIsSpinningUntil[i] = buf[ptr++];
-    diskIsSpinningUntil[i] <<= 8; diskIsSpinningUntil[i] |= buf[ptr++];
-    diskIsSpinningUntil[i] <<= 8; diskIsSpinningUntil[i] |= buf[ptr++];
-    diskIsSpinningUntil[i] <<= 8; diskIsSpinningUntil[i] |= buf[ptr++];
-    diskIsSpinningUntil[i] <<= 8; diskIsSpinningUntil[i] |= buf[ptr++];
-    diskIsSpinningUntil[i] <<= 8; diskIsSpinningUntil[i] |= buf[ptr++];
-    diskIsSpinningUntil[i] <<= 8; diskIsSpinningUntil[i] |= buf[ptr++];
-    diskIsSpinningUntil[i] <<= 8; diskIsSpinningUntil[i] |= buf[ptr++];
+    uint8_t hasDisk;
+    deserialize8(hasDisk);
     
-    if (disk[i])
-      delete disk[i];
-    if (g_filemanager->read(fd, buf, 1) != 1)
-      return false;
-    if (buf[0]) {
+    if (disk[i]) delete disk[i];
+    if (hasDisk) {
       disk[i] = new WozSerializer();
 
-      ptr = 0;
       // FIXME: MAXPATH check!
-      while (1) {
-	if (g_filemanager->read(fd, &buf[ptr++], 1) != 1)
-	  return false;
-	if (buf[ptr-1] == 0)
-	  break;
-      }
-      if (buf[0]) {
-	// Important we don't read all the tracks, so we can also flush
-	// writes back to the fd...
-	disk[i]->readFile((char *)buf, false, T_AUTO); // FIXME error checking    
+      char fn[MAXPATH];
+      deserializeString(fn);
+      if (fn[0]) {
+	printf("Restoring disk image named '%s'\n", fn);
+	disk[i]->readFile((char *)fn, false, T_AUTO); // FIXME error checking    
       } else {
 	// ERROR: there's a disk but we don't have the path to its image?
-	return false;
+	printf("Failed to read inserted disk name for disk %d\n", i);
+	goto err;
       }
       
-      if (!disk[i]->Deserialize(fd))
-	return false;
+      if (!disk[i]->Deserialize(fd)) {
+	printf("Failed to deserialize disk %d\n", i);
+	goto err;
+      }
     } else {
       disk[i] = NULL;
     }
   }
 
-  if (g_filemanager->read(fd, buf, 1) != 1)
-    return false;
-  if (buf[0] != DISKIIMAGIC)
-    return false;
+  deserializeMagic(DISKIIMAGIC);
 
   return true;
+  
+ err:
+  return false;
 }
 
 void DiskII::Reset()
diff --git a/apple/hd32.cpp b/apple/hd32.cpp
index 4837d39..f05030c 100644
--- a/apple/hd32.cpp
+++ b/apple/hd32.cpp
@@ -12,6 +12,7 @@
 #ifdef TEENSYDUINO
 #include <Arduino.h>
 #include "teensy-println.h"
+#include "iocompat.h"
 #else
 #include <unistd.h>
 #include <fcntl.h>
@@ -23,6 +24,8 @@
 
 #include "applemmu.h" // for FLOATING
 
+#include "serialize.h"
+
 #include "globals.h"
 
 #include "hd32-rom.h"
@@ -66,92 +69,58 @@ HD32::~HD32()
 
 bool HD32::Serialize(int8_t fd)
 {
-  uint8_t buf[19] = { HD32MAGIC,
-		      driveSelected,
-		      unitSelected,
-		      command,
-		      enabled,
-		      errorState[0],
-		      errorState[1],
-		      (uint8_t)((memBlock[0] >> 8) & 0xFF),
-		      (uint8_t)((memBlock[0]     ) & 0xFF),
-		      (uint8_t)((memBlock[1] >> 8) & 0xFF),
-		      (uint8_t)((memBlock[1]     ) & 0xFF),
-		      (uint8_t)((cursor[0] >> 24) & 0xFF),
-		      (uint8_t)((cursor[0] >> 16) & 0xFF),
-		      (uint8_t)((cursor[0] >>  8) & 0xFF),
-		      (uint8_t)((cursor[0]      ) & 0xFF),
-		      (uint8_t)((cursor[1] >> 24) & 0xFF),
-		      (uint8_t)((cursor[1] >> 16) & 0xFF),
-		      (uint8_t)((cursor[1] >>  8) & 0xFF),
-		      (uint8_t)((cursor[1]      ) & 0xFF)
-  };
-  if (g_filemanager->write(fd, buf, 19) != 10)
-    return false;
+  serializeMagic(HD32MAGIC);
+  serialize8(driveSelected);
+  serialize8(unitSelected);
+  serialize8(command);
+  serialize8(enabled);
+  serialize8(errorState[0]);
+  serialize8(errorState[1]);
+  serialize16(memBlock[0]);
+  serialize16(memBlock[1]);
+  serialize32(cursor[0]);
+  serialize32(cursor[1]);
 
   for (int i=0; i<2; i++) {
     const char *fn = diskName(i);
-    if (g_filemanager->write(fd, fn, strlen(fn)+1) != strlen(fn)+1) {
-      return false;
-    }
+    serializeString(fn);
   }
+  serializeMagic(HD32MAGIC);
+  return true;
 
-  buf[0] = HD32MAGIC;
-  return (g_filemanager->write(fd, buf, 1) == 1);
+ err:
+  return false;
 }
 
 bool HD32::Deserialize(int8_t fd)
 {
-  uint8_t buf[255];
-  if (g_filemanager->read(fd, buf, 19) != 19) {
-    return false;
-  }
-  if (buf[0] != HD32MAGIC)
-    return false;
-
-  driveSelected = buf[1];
-  unitSelected = buf[2];
-  command = buf[3];
-  enabled = buf[4];
-  errorState[0] = buf[5];
-  errorState[1] = buf[6];
-  memBlock[0] = buf[7];
-  memBlock[0] <<= 8; memBlock[0] |= buf[8];
-  memBlock[1] = buf[9];
-  memBlock[1] <<= 8; memBlock[1] |= buf[10];
-  cursor[0] = buf[11];
-  cursor[0] <<= 8; cursor[0] |= buf[12];
-  cursor[0] <<= 8; cursor[0] |= buf[13];
-  cursor[0] <<= 8; cursor[0] |= buf[14];
-  cursor[1] = buf[15];
-  cursor[1] <<= 8; cursor[1] |= buf[16];
-  cursor[1] <<= 8; cursor[1] |= buf[17];
-  cursor[1] <<= 8; cursor[1] |= buf[18];
+  deserializeMagic(HD32MAGIC);
 
+  deserialize8(driveSelected);
+  deserialize8(unitSelected);
+  deserialize8(command);
+  deserialize8(enabled);
+  deserialize8(errorState[0]);
+  deserialize8(errorState[1]);
+  deserialize16(memBlock[0]);
+  deserialize16(memBlock[1]);
+  deserialize32(cursor[0]);
+  deserialize32(cursor[1]);
+  
   cachedBlockNum = -1; // just invalidate the cache; it will reload...
 
   for (int i=0; i<2; i++) {
-    uint32_t ptr = 0;
-    // FIXME: MAXPATH check!                                                  
-    while (1) {
-      if (g_filemanager->read(fd, &buf[ptr++], 1) != 1)
-	return false;
-      if (buf[ptr-1] == 0)
-	break;
-    }
-    if (strlen((char *)buf)) {
-      // FIXME: this tromps on error and some other vars ... that we just restored
-      insertDisk(i, (char *)buf);
-    }
+    char buf[MAXPATH];
+    deserializeString(buf);
+    // FIXME: this tromps on error and some other vars ... that we just restored
+    insertDisk(i, (char *)buf);
   }
 
-  if (g_filemanager->read(fd, buf, 1) != 1)
-    return false;
-
-  if (buf[0] != HD32MAGIC)
-    return false;
-
+  deserializeMagic(HD32MAGIC);
+  
   return true;
+ err:
+  return false;
 }
 
 void HD32::Reset()
diff --git a/apple/woz-serializer.cpp b/apple/woz-serializer.cpp
index 926182a..890d3eb 100644
--- a/apple/woz-serializer.cpp
+++ b/apple/woz-serializer.cpp
@@ -1,6 +1,12 @@
 #include "woz-serializer.h"
 #include "globals.h"
 
+#include "serialize.h"
+
+#ifdef TEENSYDUINO
+#include "iocompat.h"
+#endif
+
 #define WOZMAGIC 0xD5
 
 WozSerializer::WozSerializer() : Woz(0,0)
@@ -20,60 +26,36 @@ bool WozSerializer::Serialize(int8_t fd)
   // If we're being asked to serialize, make sure we've flushed any data first
   flush();
 
-  uint8_t buf[17] = { WOZMAGIC,
-		      (trackPointer >> 24) & 0xFF,
-		      (trackPointer >> 16) & 0xFF,
-		      (trackPointer >>  8) & 0xFF,
-		      (trackPointer      ) & 0xFF,
-		      (trackBitCounter >> 24) & 0xFF,
-		      (trackBitCounter >> 16) & 0xFF,
-		      (trackBitCounter >>  8) & 0xFF,
-		      (trackBitCounter      ) & 0xFF,
-		      (lastReadPointer >> 24) & 0xFF,
-		      (lastReadPointer >> 16) & 0xFF,
-		      (lastReadPointer >>  8) & 0xFF,
-		      (lastReadPointer      ) & 0xFF,
-		      trackByte,
-		      trackBitIdx,
-		      trackLoopCounter,
-		      WOZMAGIC };
-  if (g_filemanager->write(fd, buf, 17) != 17)
-    return false;
+  serializeMagic(WOZMAGIC);
+  serialize32(trackPointer);
+  serialize32(trackBitCounter);
+  serialize32(lastReadPointer);
+  serialize8(trackByte);
+  serialize8(trackBitIdx);
+  serialize8(trackLoopCounter);
+  serializeMagic(WOZMAGIC);
   
   return true;
+
+ err:
+  return false;
 }
 
 bool WozSerializer::Deserialize(int8_t fd)
 {
   // Before deserializing, the caller has to re-load the right disk image!
-  uint8_t buf[17];
-  if (g_filemanager->read(fd, buf, 17) != 17)
-    return false;
-
-  if (buf[0] != WOZMAGIC)
-    return false;
-  
-  trackPointer = buf[1];
-  trackPointer <<= 8; trackPointer |= buf[2];
-  trackPointer <<= 8; trackPointer |= buf[3];
-  trackPointer <<= 8; trackPointer |= buf[4];
-
-  trackBitCounter = buf[5];
-  trackBitCounter <<= 8; trackBitCounter |= buf[6];
-  trackBitCounter <<= 8; trackBitCounter |= buf[7];
-  trackBitCounter <<= 8; trackBitCounter |= buf[8];
-
-  lastReadPointer = buf[9];
-  lastReadPointer <<= 8; lastReadPointer |= buf[10];
-  lastReadPointer <<= 8; lastReadPointer |= buf[11];
-  lastReadPointer <<= 8; lastReadPointer |= buf[12];
-
-  trackByte = buf[13];
-  trackBitIdx = buf[14];
-  trackLoopCounter = buf[15];
-  if (buf[16] != WOZMAGIC)
-    return false;
+  deserializeMagic(WOZMAGIC);
+  deserialize32(trackPointer);
+  deserialize32(trackBitCounter);
+  deserialize32(lastReadPointer);
+  deserialize8(trackByte);
+  deserialize8(trackBitIdx);
+  deserialize8(trackLoopCounter);
+  deserializeMagic(WOZMAGIC);
   
   return true;
+
+ err:
+  return false;
 }
 
diff --git a/cpu.cpp b/cpu.cpp
index 7738457..532a3b1 100644
--- a/cpu.cpp
+++ b/cpu.cpp
@@ -7,10 +7,13 @@
 #include <unistd.h>
 #include "mmu.h"
 
+#include "serialize.h"
+
 #include "globals.h"
 
 #ifdef TEENSYDUINO
 #include "teensy-println.h"
+#include "iocompat.h"
 #endif
 
 // define DEBUGSTEPS to show disassembly of each instruction as it's processed
@@ -320,74 +323,54 @@ Cpu::~Cpu()
   mmu = NULL;
 }
 
-bool Cpu::Serialize(int8_t fh)
+bool Cpu::Serialize(int8_t fd)
 {
-  uint8_t buf[13] = { CPUMAGIC,
-		      (uint8_t)((pc >> 8) & 0xFF),
-		      (uint8_t)((pc     ) & 0xFF),
-		      sp,
-		      a,
-		      x,
-		      y,
-		      flags,
-		      (uint8_t)((cycles >> 24) & 0xFF),
-		      (uint8_t)((cycles >> 16) & 0xFF),
-		      (uint8_t)((cycles >>  8) & 0xFF),
-		      (uint8_t)((cycles      ) & 0xFF),
-		      irqPending ? (uint8_t)1 : (uint8_t)0 };
+  serializeMagic(CPUMAGIC);
+  serialize16(pc);
+  serialize8(sp);
+  serialize8(a);
+  serialize8(x);
+  serialize8(y);
+  serialize8(flags);
+  serialize32(cycles);
+  serialize8(irqPending ? 1 : 0);
 
-  if (g_filemanager->write(fh, buf, 13) != 13)
-    return false;
-
-  if (!mmu->Serialize(fh)) {
-#ifndef TEENSYDUINO
+  if (!mmu->Serialize(fd)) {
     printf("MMU serialization failed\n");
-#else
-    println("MMU serialization failed");
-#endif
-    return false;
+    goto err;
   }
-
-  if (g_filemanager->write(fh, buf, 1) != 1) 
-    return false;
+  serializeMagic(CPUMAGIC);
 
   return true;
+  
+ err:
+  return false;
 }
 
-bool Cpu::Deserialize(int8_t fh)
+bool Cpu::Deserialize(int8_t fd)
 {
-  uint8_t buf[13];
-  if (g_filemanager->read(fh, buf, 13) != 13)
-    return false;
-  if (buf[0] != CPUMAGIC)
-    return false;
-  pc = (buf[1] << 8) | buf[2];
-  sp = buf[3];
-  a = buf[4];
-  x = buf[5];
-  y = buf[6];
-  flags = buf[7];
-
-  cycles = (buf[8] << 24) | (buf[9] << 16) | (buf[10] << 8) | buf[11];
-
-  irqPending = buf[12];
-
-  if (!mmu->Deserialize(fh)) {
-#ifndef TEENSYDUINO
+  deserializeMagic(CPUMAGIC);
+  deserialize16(pc);
+  deserialize8(sp);
+  deserialize8(a);
+  deserialize8(x);
+  deserialize8(y);
+  deserialize8(flags);
+  deserialize32(cycles);
+  deserialize8(irqPending);
+  
+  if (!mmu->Deserialize(fd)) {
     printf("MMU deserialization failed\n");
-#endif
     return false;
   }
 
-  if (g_filemanager->read(fh, buf, 1) != 1)
-    return false;
-  if (buf[0] != CPUMAGIC)
-    return false;
+  deserializeMagic(CPUMAGIC);
 
-#ifndef TEENSYDUINO
   printf("CPU deserialization complete\n");
-#endif
   return true;
+
+ err:
+  return false;
 }
 
 void Cpu::Reset()
diff --git a/globals.cpp b/globals.cpp
index e9e683d..e614a4c 100644
--- a/globals.cpp
+++ b/globals.cpp
@@ -19,3 +19,7 @@ bool g_invertPaddleX = false;
 bool g_invertPaddleY = false;
 
 char debugBuf[255];
+
+#ifdef TEENSYDUINO
+char fsbuf[200];
+#endif
diff --git a/globals.h b/globals.h
index d8fda9a..5edd239 100644
--- a/globals.h
+++ b/globals.h
@@ -56,4 +56,8 @@ extern bool g_invertPaddleY;
 
 extern char debugBuf[255];
 
+#ifdef TEENSYDUINO
+extern char fsbuf[200];
+#endif
+
 #endif
diff --git a/nix/nix-filemanager.cpp b/nix/nix-filemanager.cpp
index 9793d16..5b8b5bc 100644
--- a/nix/nix-filemanager.cpp
+++ b/nix/nix-filemanager.cpp
@@ -194,33 +194,43 @@ void NixFileManager::seekToEnd(int8_t fd)
 
 int NixFileManager::write(int8_t fd, const void *buf, int nbyte)
 {
-  if (fd < 0 || fd >= numCached)
+  if (fd < 0 || fd >= numCached) {
+    printf("invalid fd (out of range)\n");
     return -1;
+  }
 
-  if (cachedNames[fd][0] == 0)
+  if (cachedNames[fd][0] == 0) {
+    printf("invalid fd (not opened)\n");
     return -1;
+  }
 
   uint32_t pos = fileSeekPositions[fd];
 
   // open, seek, write, close.
-  bool ret = false;
+  ssize_t rv = 0;
   int ffd = ::open(cachedNames[fd], O_WRONLY|O_CREAT, 0644);
-  if (ffd != -1) {
-    if (::lseek(ffd, pos, SEEK_SET) == -1) {
-      close(ffd);
-      return -1;
-    }
-    ssize_t rv = ::write(ffd, buf, nbyte);
-    if (rv != nbyte) {
-      printf("error writing: %d; wanted to write %d got %d\n", errno, nbyte, ret);
-    }
-    close(ffd);
-  } else {
+  if (ffd == -1) {
     printf("Failed to open '%s' for writing: %d\n", 
 	   cachedNames[fd], errno);
+    close(ffd);
+    return -1;
   }
+  
+  if (::lseek(ffd, pos, SEEK_SET) == -1) {
+    printf("failed to open and seek\n");
+    close(ffd);
+    return -1;
+  }
+  
+  rv = ::write(ffd, buf, nbyte);
+  if (rv != nbyte) {
+    printf("error writing: %d; wanted to write %d got %ld\n", errno, nbyte, rv);
+  }
+  
+  close(ffd);
+
   fileSeekPositions[fd]+=nbyte;
-  return ret;
+  return (int)rv;
 };
 
 int NixFileManager::read(int8_t fd, void *buf, int nbyte)
diff --git a/teensy/fscompat.h b/teensy/fscompat.h
index 0fc0830..1fd1a8a 100644
--- a/teensy/fscompat.h
+++ b/teensy/fscompat.h
@@ -16,8 +16,4 @@
 #define read(filedes,buf,nbyte) g_filemanager->read(filedes,buf,nbyte)
 #define lseek(filedes,offset,whence) g_filemanager->lseek(filedes,offset,whence)
 
-static char fsbuf[200];
-#define printf(x, ...) {sprintf(fsbuf, x, ##__VA_ARGS__); Serial.println(fsbuf); Serial.flush(); Serial.send_now();}
-#define fprintf(f, x, ...) {sprintf(fsbuf, x, ##__VA_ARGS__); Serial.println(fsbuf); Serial.flush(); Serial.send_now();}
-#define perror(x) {Serial.println(x);Serial.flush(); Serial.send_now();}
-  
+#include "iocompat.h"
diff --git a/teensy/iocompat.h b/teensy/iocompat.h
new file mode 100644
index 0000000..94531ce
--- /dev/null
+++ b/teensy/iocompat.h
@@ -0,0 +1,12 @@
+#ifndef __IOCOMPAT_H
+#define __IOCOMPAT_H
+
+#include "globals.h"
+#include <Arduino.h>
+
+#define printf(x, ...) {sprintf(fsbuf, x, ##__VA_ARGS__); Serial.println(fsbuf); Serial.flush(); Serial.send_now();}
+#define fprintf(f, x, ...) {sprintf(fsbuf, x, ##__VA_ARGS__); Serial.println(fsbuf); Serial.flush(); Serial.send_now();}
+#define perror(x) {Serial.println(x);Serial.flush(); Serial.send_now();}
+  
+
+#endif
diff --git a/teensy/teensy-filemanager.cpp b/teensy/teensy-filemanager.cpp
index 44b4f48..5c24a80 100644
--- a/teensy/teensy-filemanager.cpp
+++ b/teensy/teensy-filemanager.cpp
@@ -9,7 +9,7 @@ static SdFat sd;
 static FsFile cacheFile;
 static FsFile outerDir;
 
-
+#include "iocompat.h"
 
 TeensyFileManager::TeensyFileManager()
 {
@@ -179,14 +179,15 @@ bool TeensyFileManager::_prepCache(int8_t fd)
     }
 
     // Open the new one
-    cacheFile.open(cachedNames[fd], O_RDWR);
+    cacheFile.open(cachedNames[fd], O_CREAT|O_RDWR);
     if (!cacheFile) {
+      printf("failed to open cacheFile\n");
       return false;
     }
     cacheFd = fd; // cache is live
   }
 
-  return true; // FIXME error handling
+  return true;
 }
 
 void TeensyFileManager::getRootPath(char *toWhere, int8_t maxLen)
@@ -225,10 +226,12 @@ int TeensyFileManager::write(int8_t fd, const void *buf, int nbyte)
 {
   // open, seek, write, close.
   if (fd < 0 || fd >= numCached) {
+    printf("no fd\n");
     return -1;
   }
 
   if (cachedNames[fd][0] == 0) {
+    printf("no name\n");
     return -1;
   }
 
@@ -237,15 +240,16 @@ int TeensyFileManager::write(int8_t fd, const void *buf, int nbyte)
   uint32_t pos = fileSeekPositions[fd];
 
   if (!cacheFile.seek(pos)) {
+    printf("can't seek to %d\n", pos);
     return -1;
   }
 
   if (cacheFile.write((const uint8_t *)buf, (size_t)nbyte) != (size_t)nbyte) {
+    printf("can't write\n");
     return -1;
   }
 
   fileSeekPositions[fd] += nbyte;
-  cacheFile.close();
   return nbyte;
 };
 
@@ -266,6 +270,7 @@ int TeensyFileManager::read(int8_t fd, void *buf, int nbyte)
   if (!cacheFile.seek(pos)) {
     return -1;
   }
+
   fileSeekPositions[fd] += nbyte;
 
   if (cacheFile.read(buf, nbyte) != nbyte) {
diff --git a/vm.h b/vm.h
index c98a02a..6eebc11 100644
--- a/vm.h
+++ b/vm.h
@@ -16,8 +16,8 @@ class VM {
   VM() { mmu=NULL; vmdisplay = NULL; hasIRQ = false;}
   virtual ~VM() { if (mmu) delete mmu; if (vmdisplay) delete vmdisplay; }
 
-  virtual void Suspend(const char *fn) = 0;
-  virtual void Resume(const char *fn) = 0;
+  virtual bool Suspend(const char *fn) = 0;
+  virtual bool Resume(const char *fn) = 0;
 
   virtual void SetMMU(MMU *mmu) { this->mmu = mmu; }
   virtual MMU *getMMU() { return mmu; }
diff --git a/vmram.cpp b/vmram.cpp
index cb07178..236de94 100644
--- a/vmram.cpp
+++ b/vmram.cpp
@@ -5,6 +5,7 @@
 
 #include "vmram.h"
 #include <string.h>
+#include "serialize.h"
 #include "globals.h"
 
 #ifdef TEENSYDUINO
@@ -55,46 +56,35 @@ uint8_t *VMRam::memPtr(uint32_t addr)
 bool VMRam::Serialize(int8_t fd)
 {
   uint32_t size = sizeof(preallocatedRam);
-  uint8_t buf[5] = { RAMMAGIC,
-		     (uint8_t)((size >> 24) & 0xFF),
-		     (uint8_t)((size >> 16) & 0xFF),
-		     (uint8_t)((size >>  8) & 0xFF),
-		     (uint8_t)((size      ) & 0xFF) };
-  if (g_filemanager->write(fd, buf, 5) != 5)
-    return false;
+  serializeMagic(RAMMAGIC);
+  serialize32(size);
 
   if (g_filemanager->write(fd, preallocatedRam, sizeof(preallocatedRam)) != sizeof(preallocatedRam))
-    return false;
-  
-  if (g_filemanager->write(fd, buf, 1) != 1)
-    return false;
+    goto err;
+
+  serializeMagic(RAMMAGIC);
 
   return true;
+
+ err:
+  return false;
 }
 
 bool VMRam::Deserialize(int8_t fd)
 {
-  uint8_t buf[5];
-  if (g_filemanager->read(fd, buf, 5) != 5)
-    return false;
-
-  if (buf[0] != RAMMAGIC)
-    return false;
-  
-  uint32_t size = (buf[1] << 24) | (buf[2] << 16) | (buf[3] << 8) | buf[4];
-
-  if (size != sizeof(preallocatedRam))
-    return false;
+  deserializeMagic(RAMMAGIC);
+  uint32_t size;
+  deserialize32(size);
 
   if (g_filemanager->read(fd, preallocatedRam, size) != size)
-    return false;
+    goto err;
 
-  if (g_filemanager->read(fd, buf, 1) != 1)
-    return false;
-  if (buf[0] != RAMMAGIC)
-    return false;
+  deserializeMagic(RAMMAGIC);
 
   return true;
+
+ err:
+  return false;
 }
 
 bool VMRam::Test()