diff --git a/game/ht.h b/game/ht.h
index 66e1219..b87625f 100644
--- a/game/ht.h
+++ b/game/ht.h
@@ -8829,10 +8829,16 @@ void HostGetSilkRect(int irc, Rect *prc) secHost;
 const word kfOfRead = 0x0001;		// same as "rb"
 const word kfOfWrite = 0x0002;		// same as "wb"
 
+#define kfSeekSet 0
+#define kfSeekCur 1
+#define kfSeekEnd 2
+
 FileHandle HostOpenFile(const char *pszFilename, word wf) secHost;
 void HostCloseFile(FileHandle hf) secHost;
-dword HostWriteFile(FileHandle hf, void *pv, dword cb) secHost;
-dword HostReadFile(FileHandle hf, void *pv, dword cb) secHost;
+dword HostWriteFile(void *pv, dword c, dword cb, FileHandle hf) secHost;
+dword HostReadFile(void *pv, dword c, dword cb, FileHandle hf) secHost;
+dword HostSeekFile(FileHandle hf, int off, int nOrigin) secHost;
+dword HostTellFile(FileHandle hf) secHost;
 
 // Save game
 
diff --git a/game/mempdbreader.cpp b/game/mempdbreader.cpp
index fe666a2..dcf33ef 100644
--- a/game/mempdbreader.cpp
+++ b/game/mempdbreader.cpp
@@ -23,28 +23,28 @@ bool MemPdbReader::Open(char *pszFn)
 	// Attempt to open
 
 	Assert(m_pb == NULL);
-	FILE *pfil = fopen(pszFn, "rb");
-	if (pfil == NULL) {
+    FileHandle hf = HostOpenFile(pszFn, kfOfRead);
+	if (hf == NULL) {
         Trace("fopen(\"%s\", \"rb\"); failed", pszFn);
 		return false;
     }
 
 	// Read in the entire thing
 
-	fseek(pfil, 0, SEEK_END);
-	m_cb = (dword)ftell(pfil);
-	fseek(pfil, 0, SEEK_SET);
+    HostSeekFile(hf, 0, kfSeekEnd);
+    m_cb = HostTellFile(hf);
+    HostSeekFile(hf, 0, kfSeekSet);
 
 	m_pb = new byte[m_cb];
 	if (m_pb == NULL) {
-		fclose(pfil);
+		HostCloseFile(hf);
 		return false;
 	}
-	if (fread(m_pb, m_cb, 1, pfil) != 1) {
-		fclose(pfil);
+	if (HostReadFile(m_pb, m_cb, 1, hf) != 1) {
+		HostCloseFile(hf);
 		return false;
 	}
-	fclose(pfil);
+	HostCloseFile(hf);
 
 	// Alloc cache handle array
 
diff --git a/game/sdl/host.cpp b/game/sdl/host.cpp
index 0c45359..aa38549 100644
--- a/game/sdl/host.cpp
+++ b/game/sdl/host.cpp
@@ -700,22 +700,44 @@ FileHandle HostOpenFile(const char *pszFilename, word wf)
     else if (wf == (kfOfRead | kfOfWrite))
         pszMode = "rb+";
 
-    return (FileHandle)fopen((char *)pszFilename, pszMode);
+    return (FileHandle)SDL_RWFromFile(pszFilename, pszMode);
 }
 
 void HostCloseFile(FileHandle hf)
 {
-    fclose((FILE *)hf);
+    SDL_RWclose((SDL_RWops *)hf);
 }
 
-dword HostWriteFile(FileHandle hf, void *pv, dword cb)
+dword HostWriteFile(void *pv, dword c, dword cb, FileHandle hf)
 {
-    return fwrite(pv, 1, cb, (FILE *)hf);
+    // SDL_RWwrite() returns the number of objects written,
+    // which will be less than cb on error
+
+    return (dword)SDL_RWwrite((SDL_RWops *)hf, pv, c, cb);
 }
 
-dword HostReadFile(FileHandle hf, void *pv, dword cb)
+dword HostReadFile(void *pv, dword c, dword cb, FileHandle hf)
 {
-    return fread(pv, 1, cb, (FILE *)hf);
+    // SDLRWread() returns the number of objects read,
+    // or 0 at error or end of file
+
+    return (dword)SDL_RWread((SDL_RWops *)hf, pv, c, cb);
+}
+
+dword HostSeekFile(FileHandle hf, int off, int nOrigin)
+{
+    // SDL_RWseek() returns the final offset in the data
+    // stream after the seek or -1 on error
+
+    return (dword)SDL_RWseek((SDL_RWops *)hf, off, nOrigin);
+}
+
+dword HostTellFile(FileHandle hf)
+{
+    // SDL_RWtell() returns the current offset in the stream,
+    // or -1 if the information can not be determined
+
+    return (dword)SDL_RWtell((SDL_RWops *)hf);
 }
 
 void HostSleep(dword ct)