diff --git a/docs/history.txt b/docs/history.txt
index 8845505..432ad6a 100644
--- a/docs/history.txt
+++ b/docs/history.txt
@@ -1,12 +1,14 @@
-2004 July 8 - UNSTABLE branch
+2005 Jan XX - UNSTABLE (-w) branch
 -------- Jeremy Davis (jeremyd@computer.org)
 + Changes Bart
-      * int2f.asm
-        - bugfix: call_nls: DI register was not preserved
       * exeflat.c
         - new version exploiting better UPX compression for SYS files; calls UPX itself
+      * int2f.asm
+        - bugfix: call_nls: DI register was not preserved
       * inthndlr.c
         - int21/ah=6/dl=ff now calls int28
+      * sys.c
+        - correct fat32readwrite's prototype to explicitly return int
 + Changes Tom
 	* inthndlr.c
 	  - improve handling of case where eg. FindFirst(I:\*.*) fails, causes Int24,
@@ -316,7 +318,7 @@
           (the last 2 changes needed to fix bugs discovered by Michael Devore)
         - added Int 2Fh/2Fh processing to set DOS version as per MS-DOS 4.0
         - optimised Int 21h/AH=38h Get Country Information, removed cntry hack
-        * autoexec.bat now single-line for FreeCOM compatibility when EOL=LF
+        * autoexec.bat: now single-line for FreeCOM compatibility when EOL=LF
         * break.c: check_handle_break() return was undefined if no Ctrl-break
         * config.sys: all commands removed as they were close to defaults
         * contrib.txt: added Aitor Santamaria, Bernd Blaauw and Eduardo Casino
@@ -330,16 +332,16 @@
           - optimisation and clean-up
         * fattab.c: ISFAT32 function removed (now macro), "wasfree" optimised
         * globals.h: __TIME__ removed - no two kernels released on same day
-        * initdisk.c:
+        * initdisk.c
           - if no floppy drives present, don't initialise DDT for drive A:
           - " - Initdisk" no longer shifts text if no FAT partitions found
           - converted cdiv() from macro to function; optimise and clean-up
         * inithma: InstallVDISK() function inlined, optimised and cleaned up
         * intr.asm: lseek() added (necessary for COUNTRY.SYS processing)
-        * ioctl.c:
+        * ioctl.c
           - r_si/r_di contents added as documented in PC-DOS Technical Update
           - r_unit now set to dpb_subunit (allows ZIP disk serial number)
-        * main.c:
+        * main.c
           - copyright message cleanup, now shows URL for the full GNU GPL text
           - (with Bart) LoL pointer made const (saves some size for Watcom)
           - InitializeAllBPBs() kludge removed (no longer needed - verified)
@@ -353,7 +355,7 @@
  + Changes Eduardo
         * config.c: update hardcoded country and codepage IDs
         * country.asm: added NLS uppercase/collating tables (437,850,857,858)
-        * inthndlr.c:
+        * inthndlr.c
           - added Int 2Fh/26-29h processing for NLSFUNC (with Lucho)
           - DOS-63-00 returns DBCS table from the active NLS package, not the
             harcoded one.
@@ -368,27 +370,44 @@
           - DosYesNo(): arg is now UWORD, not unsigned char.
           - nlsYesNo(): Add DBCS support
           - syscall_MUX14(): arg of nlsYesNo() is now CX instead of CL.
-        * nls.h:
+        * nls.h
           - yeschar and nochar are now UWORD instead of UBYTE.
           - NLS_FREEDOS_NLSFUNC_VERSION bumped to 0xFD02.
           - Add a small comment.
         * nls_hc.asm: YesChar and NoChar are now two bytes each.
-        * proto.h:
+        * proto.h
           - DosYesNo(): Argument is now UWORD (dual byte)
           - Add prototype for DosGetDBCS()
  + Changes Jeremy
-        * config.txt
-          - update to include all CONFIG.SYS options (except ANYDOS)
+        * updated build system to use NT OW binaries when building on NT
+          and add some additional options to build.bat command line
+        * added debug.h and changed to more easily allow selective DEBUG output
         * boot.asm
           - use static read buffer to avoid crossing 64KB boundary
+          - drop test for drive==0xFF, use sys to NOP use of BIOS provided #
+        * config.c
+          - always initialize boot time master environment
+          - KernelAlloc always 0's returned memory (fixes potential boot
+            time failure finding/loading CONFIG.SYS)
+        * config.txt
+          - update to include all CONFIG.SYS options (except ANYDOS)
+        * exeflat.c
+          - show usage also when number of arguments incorrect
+        * fatdir.c
+          - be more restrictive in what considered a volume search
+        * initdisk.c
+          - set hidden & huge fields in floppy bpb (bugfix 1789)
         * main.c
           - treat block devices returning 0 units as load failure
         * oemboot.asm - add [optional] PC/MS DOS compatible boot sector
         * sys.c
           - incorporate changes from/for DR-DOS enhancement project
           - rework option handling, add backup & restore boot sector
-        * exeflat.c
-          - show usage also when number of arguments incorrect
+          - change boot time drive selection (BIOS provided or one in
+            boot sector) to be selected as SYS time via NOPing mov [drive],dl
+        * add sys.txt (documentation) and sys.html (htmlhelp file)
+        * task.c
+          - add debug output to see env & cmd line passed to exec'd program
         < many other changes to be added by Jeremy himself :->
 
 *** Sync - Stable Build 2035 ***
diff --git a/hdr/debug.h b/hdr/debug.h
index f2ef7f3..d4cf7f1 100644
--- a/hdr/debug.h
+++ b/hdr/debug.h
@@ -55,6 +55,13 @@
 /* show stored IRQ vectors */
 /* #define DEBUGIRQ */
 
+/* show output related to moving kernel into HMA */
+#ifdef DEBUG
+#define HMAInitPrintf(x) printf x
+#else
+#define HMAInitPrintf(x)
+#endif
+
 /* display output during kernel config processing phase */
 /* #define DEBUGCFG */
 #ifdef DEBUGCFG
diff --git a/hdr/lol.h b/hdr/lol.h
index b0cb59e..ff2174b 100644
--- a/hdr/lol.h
+++ b/hdr/lol.h
@@ -26,7 +26,8 @@
 /* Boston, MA  02111-1307  USA.                                 */
 /****************************************************************/
 
-enum {LOC_CONV=0, LOC_HMA=1};
+#ifndef __LOL_H
+#define __LOL_H
 
 /* note: we start at DOSDS:0, but the "official" list of lists starts a
    little later at DOSDS:26 (this is what is returned by int21/ah=52) */
@@ -84,3 +85,5 @@ struct lol {
   unsigned short f_nodes_cnt;  /* 74 number of allocated f_nodes          */
   char *os_release;            /* 76 near pointer to os_release string    */
 };
+
+#endif /* __LOL_H */
diff --git a/kernel/dosfns.c b/kernel/dosfns.c
index 7ef142c..8a8b40a 100644
--- a/kernel/dosfns.c
+++ b/kernel/dosfns.c
@@ -27,6 +27,7 @@
 /****************************************************************/
 
 #include "portab.h"
+#include "debug.h"
 
 #ifdef VERSION_STRINGS
 static BYTE *dosfnsRcsId =
@@ -504,11 +505,19 @@ long DosOpenSft(char FAR * fname, unsigned flags, unsigned attrib)
 
   result = truename(fname, PriPathName, CDS_MODE_CHECK_DEV_PATH);
   if (result < SUCCESS)
+  {
+    DFnsDbgPrintf(("DosOpenSft: truename failed\n"));
     return result;
+  }
+  else DFnsDbgPrintf(("DosOpenSft: truename succeeded\n"));
 
   /* now get a free system file table entry       */
   if ((sftp = get_free_sft(&sft_idx)) == (sft FAR *) - 1)
+  {
+    DFnsDbgPrintf(("DosOpenSft: file table full\n"));
     return DE_TOOMANY;
+  }
+  else DFnsDbgPrintf(("DosOpenSft: obtained sft entry\n"));
 
   fmemset(sftp, 0, sizeof(sft));
 
@@ -519,10 +528,14 @@ long DosOpenSft(char FAR * fname, unsigned flags, unsigned attrib)
   sftp->sft_shroff = -1;        /* /// Added for SHARE - Ron Cemer */
   sftp->sft_attrib = attrib = attrib | D_ARCHIVE;
 
+  DFnsDbgPrintf(("DosOpenSft: mode=%02X, flags=%02X, attrib=%02X\n", \
+               sftp->sft_mode, OpenMode, attrib));
+
   if (result & IS_NETWORK)
   {
     int status;
     unsigned cmd;
+    DFnsDbgPrintf(("DosOpenSft: IS_NETWORK\n"));
     if ((flags & (O_TRUNC | O_CREAT)) == O_CREAT)
       attrib |= 0x100;
 
@@ -558,6 +571,7 @@ long DosOpenSft(char FAR * fname, unsigned flags, unsigned attrib)
     /* check the status code returned by the
      * driver when we tried to open it
      */
+    DFnsDbgPrintf(("DosOpenSft: IS_DEVICE\n"));
     if (rc < SUCCESS)
       return rc;
     return sft_idx;
@@ -566,6 +580,7 @@ long DosOpenSft(char FAR * fname, unsigned flags, unsigned attrib)
 /* /// Added for SHARE.  - Ron Cemer */
   if (IsShareInstalled())
   {
+    DFnsDbgPrintf(("DosOpenSft: using SHARE\n"));
     if ((sftp->sft_shroff =
          share_open_check(PriPathName, cu_psp,
                           flags & 0x03, (flags >> 4) & 0x07)) < 0)
@@ -578,9 +593,13 @@ long DosOpenSft(char FAR * fname, unsigned flags, unsigned attrib)
   /* ... though FCB's are weird :) */
   if (!(flags & O_FCB) &&
       (attrib & ~(D_RDONLY | D_HIDDEN | D_SYSTEM | D_ARCHIVE | D_VOLID)))
+  {
+    DFnsDbgPrintf(("DosOpenSft: invalid request\n"));
     return DE_ACCESS;
+  }
   
   result = dos_open(PriPathName, flags, attrib);
+  DFnsDbgPrintf(("DosOpenSft: dos_open returned %02X\n", result));
   if (result >= 0)
   {
     int status = (int)(result >> 16);
@@ -591,6 +610,7 @@ long DosOpenSft(char FAR * fname, unsigned flags, unsigned attrib)
          (do not allow to open volume labels/directories) */
       if (sftp->sft_attrib & (D_DIR | D_VOLID))
       {
+        DFnsDbgPrintf(("DosOpenSft: closing, invalid attributes DIR|VOLID\n"));
         dos_close((COUNT)result);
         return DE_ACCESS;
       }
@@ -603,6 +623,7 @@ long DosOpenSft(char FAR * fname, unsigned flags, unsigned attrib)
     dos_getftime(sftp->sft_status,
                  (date FAR *) & sftp->sft_date,
                  (time FAR *) & sftp->sft_time);
+    DFnsDbgPrintf(("DosOpenSft: returning %lu (decimal)\n", (sft_idx | ((long)status << 16))));
     return sft_idx | ((long)status << 16);
   }
   else
@@ -944,7 +965,6 @@ COUNT DosGetCuDir(UBYTE drive, BYTE FAR * s)
   return SUCCESS;
 }
 
-#undef CHDIR_DEBUG
 COUNT DosChangeDir(BYTE FAR * s)
 {
   COUNT result;
diff --git a/kernel/dyninit.c b/kernel/dyninit.c
index 9350072..0461e55 100644
--- a/kernel/dyninit.c
+++ b/kernel/dyninit.c
@@ -38,12 +38,7 @@ additionally:
 #include "portab.h"
 #include "init-mod.h"
 #include "dyndata.h"
-
-#if defined(DEBUG)
-#define DebugPrintf(x) printf x
-#else
-#define DebugPrintf(x)
-#endif
+#include "debug.h"
 
 /*extern struct DynS FAR Dyn;*/
 
diff --git a/kernel/fatdir.c b/kernel/fatdir.c
index b66ce08..c7c98dd 100644
--- a/kernel/fatdir.c
+++ b/kernel/fatdir.c
@@ -29,6 +29,7 @@
 
 #include "portab.h"
 #include "globals.h"
+#include "debug.h"
 
 #ifdef VERSION_STRINGS
 static BYTE *fatdirRcsId =
@@ -62,9 +63,12 @@ f_node_ptr dir_open(register const char *dirname)
   int i;
   char fcbname[FNAME_SIZE + FEXT_SIZE];
 
+  FDirDbgPrintf(("dir_open: trying to open %s\n", dirname));
+  
   /* Allocate an fnode if possible - error return (0) if not.     */
   if ((fnp = get_f_node()) == (f_node_ptr) 0)
   {
+    FDirDbgPrintf(("dir_open: failed to get f_node\n"));
     return (f_node_ptr) 0;
   }
 
@@ -78,6 +82,7 @@ f_node_ptr dir_open(register const char *dirname)
 
   if (media_check(fnp->f_dpb) < 0)
   {
+    FDirDbgPrintf(("dir_open: media_check failed\n"));
     release_f_node(fnp);
     return (f_node_ptr) 0;
   }
@@ -136,6 +141,7 @@ f_node_ptr dir_open(register const char *dirname)
 
     if (!i || !(fnp->f_dir.dir_attrib & D_DIR))
     {
+      FDirDbgPrintf(("dir_open: no match found, returning failure\n"));
       release_f_node(fnp);
       return (f_node_ptr) 0;
     }
@@ -146,6 +152,7 @@ f_node_ptr dir_open(register const char *dirname)
       dir_init_fnode(fnp, getdstart(fnp->f_dpb, &fnp->f_dir));
     }
   }
+  FDirDbgPrintf(("dir_open: returning, ok\n"));
   return fnp;
 }
 
@@ -188,7 +195,10 @@ COUNT dir_read(REG f_node_ptr fnp)
 
   /* can't have more than 65535 directory entries */
   if (fnp->f_diroff >= 65535U)
+  {
+      FDirDbgPrintf(("dir_read: exceed dir entry count\n"));
       return DE_SEEK;
+  }
 
   /* Determine if we hit the end of the directory. If we have,    */
   /* bump the offset back to the end and exit. If not, fill the   */
@@ -198,7 +208,10 @@ COUNT dir_read(REG f_node_ptr fnp)
   if (fnp->f_dirstart == 0)
   {
     if (fnp->f_diroff >= fnp->f_dpb->dpb_dirents)
+    {
+      FDirDbgPrintf(("dir_read: end of dir\n"));
       return DE_SEEK;
+    }
 
     bp = getblock(fnp->f_diroff / (secsize / DIRENT_SIZE)
                            + fnp->f_dpb->dpb_dirstrt, fnp->f_dpb->dpb_unit);
@@ -217,7 +230,10 @@ COUNT dir_read(REG f_node_ptr fnp)
     printf("dir_read: ");
 #endif
     if (map_cluster(fnp, XFR_READ) != SUCCESS)
+    {
+      DebugPrintf(("dir_read: map_cluster failed\n"));
       return DE_SEEK;
+    }
 
     bp = getblock_from_off(fnp, secsize);
 #ifdef DISPLAY_GETBLOCK
@@ -228,7 +244,10 @@ COUNT dir_read(REG f_node_ptr fnp)
   /* Now that we have the block for our entry, get the    */
   /* directory entry.                                     */
   if (bp == NULL)
+  {
+    FDirDbgPrintf(("dir_read: invalid block\n"));
     return DE_BLKINVLD;
+  }
 
   bp->b_flag &= ~(BFR_DATA | BFR_FAT);
   bp->b_flag |= BFR_DIR | BFR_VALID;
@@ -245,6 +264,7 @@ COUNT dir_read(REG f_node_ptr fnp)
   /* and for efficiency, stop when we hit the first       */
   /* unused entry.                                        */
   /* either returns 1 or 0                                */
+  FDirDbgPrintf(("dir_read: dir_name is %11s\n", fnp->f_dir.dir_name));
   return (fnp->f_dir.dir_name[0] != '\0');
 }
 
@@ -423,9 +443,8 @@ COUNT dos_findfirst(UCOUNT attr, BYTE * name)
       {
         dmp->dm_dircluster = fnp->f_dirstart;   /* TE */
         memcpy(&SearchDir, &fnp->f_dir, sizeof(struct dirent));
-#ifdef DEBUG
-        printf("dos_findfirst: %11s\n", fnp->f_dir.dir_name);
-#endif
+        FDirDbgPrintf(("dos_findfirst: %11s\n", fnp->f_dir.dir_name));
+
         dir_close(fnp);
         return SUCCESS;
       }
@@ -511,9 +530,7 @@ COUNT dos_findnext(void)
       return SUCCESS;
     }
   }
-#ifdef DEBUG
-  printf("dos_findnext: %11s\n", fnp->f_dir.dir_name);
-#endif
+  FDirDbgPrintf(("dos_findnext: %11s\n", fnp->f_dir.dir_name));
   /* return the result                                            */
   release_f_node(fnp);
 
diff --git a/kernel/fatfs.c b/kernel/fatfs.c
index 8e010a3..9012a07 100644
--- a/kernel/fatfs.c
+++ b/kernel/fatfs.c
@@ -29,6 +29,7 @@
 
 #include "portab.h"
 #include "globals.h"
+#include "debug.h"
 
 #ifdef VERSION_STRINGS
 BYTE *RcsId = "$Id$";
@@ -142,12 +143,16 @@ long dos_open(char *path, unsigned flags, unsigned attrib)
   /* next, split the passed dir into components (i.e. - path to   */
   /* new directory and name of new directory.                     */
   if ((fnp = split_path(path, fcbname)) == NULL)
+  {
+    FatFSDbgPrintf(("dos_open: splitpath(\"%s\", \"%11s\") failed.\n", path, fcbname));
     return DE_PATHNOTFND;
+  }
 
   /* Check that we don't have a duplicate name, so if we  */
   /* find one, truncate it (O_CREAT).                     */
   if (find_fname(fnp, fcbname, D_ALL | attrib))
   {
+    FatFSDbgPrintf(("dos_open: filename match found\n"));
     if (flags & O_TRUNC)
     {
       /* The only permissable attribute is archive,   */
@@ -189,6 +194,7 @@ long dos_open(char *path, unsigned flags, unsigned attrib)
   else if (flags & O_CREAT)
   {
     int ret = alloc_find_free(fnp, path, fcbname);
+    FatFSDbgPrintf(("dos_open: create\n"));
     if (ret != SUCCESS)
       return ret;
     status = S_CREATED;
@@ -198,6 +204,7 @@ long dos_open(char *path, unsigned flags, unsigned attrib)
     /* open: If we can't find the file, just return a not    */
     /* found error.                                          */
     dir_close(fnp);
+    FatFSDbgPrintf(("dos_open: file not found\n"));
     return DE_FILENOTFND;
   }
   
@@ -312,6 +319,8 @@ f_node_ptr split_path(char * path, char * fcbname)
 
   /* Start off by parsing out the components.                     */ 
   int dirlength = ParseDosName(path, fcbname, FALSE);
+  FatFSDbgPrintf(("split_path: dirlen=%i, path=\"%s\", fcbname=\"%11s\"\n", \
+                dirlength, path, fcbname));
 
   if (dirlength < SUCCESS)
     return (f_node_ptr) 0;
@@ -330,7 +339,7 @@ f_node_ptr split_path(char * path, char * fcbname)
 #ifdef DEBUG
   if (get_cds(path[0]-'A')->cdsFlags & CDSNETWDRV)
   {
-    printf("split path called for redirected file: `%s'\n",
+    printf("split path called for redirected file: `%11s'\n",
            fcbname);
     return (f_node_ptr) 0;
   }
@@ -349,10 +358,14 @@ f_node_ptr split_path(char * path, char * fcbname)
   /* note: an invalid fd is indicated by a 0 return               */
   if (fnp == (f_node_ptr) 0 || fnp->f_count <= 0)
   {
+    FatFSDbgPrintf(("split_path: failing, fnp is %sNULL, f_count=%i\n", \
+                 (fnp==(f_node_ptr)0)?"":"NOT", \
+                 (fnp==(f_node_ptr)0)?123:fnp->f_count));
     dir_close(fnp);
     return (f_node_ptr) 0;
   }
 
+  FatFSDbgPrintf(("split_path: success\n"));
   return fnp;
 }
 
@@ -1817,18 +1830,18 @@ int dos_cd(char * PathName)
 
 /* try to allocate a near f_node                            */
 /* (there are just two of them, in the SDA)                 */
-
 f_node_ptr get_near_f_node(void)
 {
   f_node_ptr fnp = fnode;
+  DebugPrintf(("get_near_f_node: fnp is %p\n", fnp));
   if (fnp->f_count && (++fnp)->f_count)
     panic("more than two near fnodes requested at the same time!\n");
   fnp->f_count++;
+  DebugPrintf(("got near fnode, fnp->f_count=%i\n", fnp->f_count));
   return fnp;
 }
 
 /* Try to allocate an f_node from the available files array */
-
 f_node_ptr get_f_node(void)
 {
   REG int i;
@@ -1836,17 +1849,22 @@ f_node_ptr get_f_node(void)
 
   if (fnp != (f_node_ptr)0)
   {
+    FatFSDbgPrintf(("get_f_node: &f_nodes[0]=%p, f_nodes_cnt=%i\n", (void far *)&f_nodes, f_nodes_cnt));
     for (i = 0; i < f_nodes_cnt; i++)
     {
       if (f_nodes[i].f_count == 0)
       {
         ++f_nodes[i].f_count;
         fnode_fd[fnp - fnode] = i;
+        FatFSDbgPrintf(("f_nodes[%i].f_count=%i, fnode_fd[%i]=%i\n", \
+               i, f_nodes[i].f_count, (fnp-fnode), i));
         return fnp;
       }
     }
     release_near_f_node(fnp);
+    FatFSDbgPrintf(("get_f_node: failure finding free entry in f_nodes[]\n"));
   }
+  else FatFSDbgPrintf(("get_f_node: get_near_fnode() failed, returned NULL\n"));
   return (f_node_ptr) 0;
 }
 
@@ -1854,6 +1872,8 @@ VOID release_f_node(f_node_ptr fnp)
 {
   struct f_node FAR *fp = &f_nodes[xlt_fnp(fnp)];
 
+  FatFSDbgPrintf(("release_f_node: fp->f_count=%i\n", fp->f_count));
+
   if (fp->f_count > 0)
     --fp->f_count;
   else
@@ -2048,28 +2068,37 @@ COUNT media_check(REG struct dpb FAR * dpbp)
   /* First test if anyone has changed the removable media         */
   ret = rqblockio(C_MEDIACHK, dpbp);
   if (ret < SUCCESS)
+  {
+    FatFSDbgPrintf(("media_check: failed\n"));
     return ret;
+  }
 
   switch (MediaReqHdr.r_mcretcode | dpbp->dpb_flags)
   {
     case M_NOT_CHANGED:
       /* It was definitely not changed, so ignore it          */
+      DebugPrintf(("media_check: no change\n"));
       return SUCCESS;
 
       /* If it is forced or the media may have changed,       */
       /* rebuild the bpb                                      */
     case M_DONT_KNOW:
         /* hazard: no error checking! */
+      DebugPrintf(("media_check: unknown\n"));
       flush_buffers(dpbp->dpb_unit);
 
       /* If it definitely changed, don't know (falls through) */
       /* or has been changed, rebuild the bpb.                */
  /* case M_CHANGED: */
     default:
+      DebugPrintf(("media_check: assumming changed\n"));
       setinvld(dpbp->dpb_unit);
       ret = rqblockio(C_BLDBPB, dpbp);
       if (ret < SUCCESS)
+      {
+        DebugPrintf(("media_check: build BPB failed\n"));
         return ret;
+      }
 #ifdef WITHFAT32
       /* extend dpb only for internal or FAT32 devices */
       bpb_to_dpb(MediaReqHdr.r_bpptr, dpbp,
@@ -2077,6 +2106,7 @@ COUNT media_check(REG struct dpb FAR * dpbp)
 #else
       bpb_to_dpb(MediaReqHdr.r_bpptr, dpbp);
 #endif
+      DebugPrintf(("media_check: returning ok\n"));
       return SUCCESS;
   }
 }
@@ -2089,19 +2119,25 @@ f_node_ptr xlt_fd(int fd)
   /* If the fd was invalid because it was out of range or the     */
   /* requested file was not open, tell the caller and exit        */
   /* note: an invalid fd is indicated by a 0 return               */
+  FatFSDbgPrintf(("xlt_fd: fd(%i) ?< f_nodes_cnt(%i)\n", fd, f_nodes_cnt));
   if (fd < f_nodes_cnt)
   {
     fnp = get_near_f_node();
     if (fnp != (f_node_ptr)0)
     {
       fmemcpy(fnp, &f_nodes[fd], sizeof(*fnp));
+      FatFSDbgPrintf(("xlt_fd: fnp->f_count=%i, fnp-fnode=%i\n", fnp->f_count, (fnp-fnode)));
       if (fnp->f_count <= 0)
       {
         release_near_f_node(fnp);
         fnp = (f_node_ptr) 0;
       } else
+      {
         fnode_fd[fnp - fnode] = fd;
+        FatFSDbgPrintf(("xlt_fd: success\n"));
+      }
     }
+    else FatFSDbgPrintf(("xlt_fd: get_near_f_node failed\n"));
   }
   return fnp;
 }
@@ -2109,6 +2145,7 @@ f_node_ptr xlt_fd(int fd)
 /* copy a near fnode to the corresponding far one and release it */
 STATIC void save_far_f_node(f_node_ptr fnp)
 {
+  FatFSDbgPrintf(("save_far_f_node: copying near fnode to far one\n"));
   fmemcpy(&f_nodes[xlt_fnp(fnp)], fnp, sizeof(*fnp));
   release_near_f_node(fnp);
 }
diff --git a/kernel/globals.h b/kernel/globals.h
index c8f912a..2696ab8 100644
--- a/kernel/globals.h
+++ b/kernel/globals.h
@@ -27,6 +27,9 @@
 /* Cambridge, MA 02139, USA.                                    */
 /****************************************************************/
 
+#ifndef __GLOBALS_H
+#define __GLOBALS_H
+
 #ifdef VERSION_STRINGS
 #ifdef MAIN
 static BYTE *Globals_hRcsId =
@@ -422,3 +425,6 @@ GLOBAL BYTE ReturnAnyDosVersionExpected;
 
 GLOBAL struct f_node fnode[2];
 GLOBAL int fnode_fd[2];
+
+#endif /* __GLOBALS_H */
+
diff --git a/kernel/inithma.c b/kernel/inithma.c
index 952d5e2..3afc67d 100644
--- a/kernel/inithma.c
+++ b/kernel/inithma.c
@@ -65,6 +65,7 @@
 
 #include "portab.h"
 #include "init-mod.h"
+#include "debug.h"
 
 #ifdef VERSION_STRINGS
 static BYTE *RcsId =
@@ -90,12 +91,6 @@ void int3()
 #define int3()
 #endif
 
-#ifdef DEBUG
-#define HMAInitPrintf(x) printf x
-#else
-#define HMAInitPrintf(x)
-#endif
-
 #ifdef DEBUG
 VOID hdump(BYTE FAR * p)
 {
@@ -295,9 +290,11 @@ void MoveKernel(unsigned NewKernelSegment)
   unsigned len;
   unsigned jmpseg = CurrentKernelSegment;
  
+  /* on 1st call use original link time (unrelocated) TGROUP segment */
   if (CurrentKernelSegment == 0)
     CurrentKernelSegment = FP_SEG(_HMATextEnd);
 
+  /* if already relocated to HMA, then ignore move request */
   if (CurrentKernelSegment == 0xffff)
     return;
 
diff --git a/kernel/irqstack.asm b/kernel/irqstack.asm
index 63dc3c7..fd55d3b 100644
--- a/kernel/irqstack.asm
+++ b/kernel/irqstack.asm
@@ -34,7 +34,8 @@
 
 segment	_LOWTEXT
 
-old_vectors     times 16 dd 0
+global _old_vectors
+_old_vectors     times 16 dd 0
 stack_size      dw      0
 stack_top       dw      0
 stack_offs      dw      0
@@ -129,7 +130,7 @@ general_irq_service:
                 sub     [stack_top], ax
 
                 pushf
-                call    far word [old_vectors+bx]
+                call    far word [_old_vectors+bx]
 
                 cli
                 add     [stack_top], ax
@@ -147,7 +148,7 @@ general_irq_service:
                 iret
 
 dont_switch:    pushf
-                call    far word [old_vectors+bx]
+                call    far word [_old_vectors+bx]
                 pop     ds
                 pop     ax
                 pop     dx
@@ -190,7 +191,7 @@ _init_stacks:
 		mov	ax, _LOWTEXT
 		mov	es, ax
 
-                mov     di, old_vectors
+                mov     di, _old_vectors
                 mov     si, 8 * 4
                 mov     cx, 10h
                 rep     movsw
diff --git a/kernel/main.c b/kernel/main.c
index 30f7cda..691ab83 100644
--- a/kernel/main.c
+++ b/kernel/main.c
@@ -234,6 +234,23 @@ STATIC void setup_int_vectors(void)
   setvec(0x29, int29_handler);  /* required for printf! */
 }
 
+#ifdef DEBUGIRQ
+extern short old_vectors;
+STATIC void printIRQvectors(void)
+{
+  int i,c=0;
+  short FAR *pv = MK_FP(0x70 /* ??? */, (short)&old_vectors);
+  printf("Original IRQ1-16 Int vectors: %x:%x\n", FP_SEG(pv), FP_OFF(pv));
+  for (i = 0; i < 16; i++, pv+=2)
+  {
+    printf("(%x)%04X:%04X ", i, *pv, *(pv+1));
+    c = (c+1)%6;
+    if (c==0) printf("\n");
+  }
+  printf("\n");
+}
+#endif
+
 STATIC void init_kernel(void)
 {
   COUNT i;
@@ -243,6 +260,8 @@ STATIC void init_kernel(void)
   LoL->rev_number = REVISION_SEQ;
 
   /* move kernel to high conventional RAM, just below the init code */
+  /* Note: kernel.asm actually moves and jumps here, but MoveKernel
+           must still be called to do the necessary segment fixups */
 #ifdef __WATCOMC__
   lpTop = MK_FP(_CS, 0);
 #else
@@ -251,6 +270,10 @@ STATIC void init_kernel(void)
 
   MoveKernel(FP_SEG(lpTop));
   /* lpTop should be para-aligned				*/
+  /* Note: during init time (before our MCB chain established)
+     KernelAlloc returns a para aligned chunk just below last
+     chunk allocated, lpTop. I.e. lpTop is top of free conv memory
+   */
   lpTop = MK_FP(FP_SEG(lpTop) - 0xfff, 0xfff0);
 
   /* Initialize IO subsystem                                      */
@@ -258,7 +281,7 @@ STATIC void init_kernel(void)
   InitPrinters();
   InitSerialPorts();
 
-  init_PSPSet(DOS_PSP);
+  init_PSPSet(DOS_PSP);  /* LoL->_cu_psp = DOS_PSP; */
   set_DTA(MK_FP(DOS_PSP, 0x80));
   PSPInit();
 
@@ -289,6 +312,11 @@ STATIC void init_kernel(void)
   /* and do final buffer allocation. */
   PostConfig();
 
+#ifdef DEBUGIRQ
+  /* displayed stored IRQ vectors, should be original values */
+  printIRQvectors();
+#endif
+
   /* Init the file system one more time     */
   FsConfig();
 
@@ -423,6 +451,10 @@ STATIC VOID update_dcb(struct dhdr FAR * dhp)
   int nunits = dhp->dh_name[0];
   struct dpb FAR *dpb = LoL->DPBp;
 
+  /* if we have already chained to at least block driver,
+     then find last DPB in list, reserve some space in
+     unused (top of convential) memory, and link it in.
+   */
   if (LoL->nblkdev)
   {
     while ((LONG) dpb->dpb_next != -1l)
diff --git a/kernel/prf.c b/kernel/prf.c
index 338d3da..cc82ba4 100644
--- a/kernel/prf.c
+++ b/kernel/prf.c
@@ -27,6 +27,7 @@
 /****************************************************************/
 
 #include "portab.h"
+#include "debug.h"
 
 #ifdef FORSYS
 #include <io.h>
@@ -118,7 +119,7 @@ void put_console(int c)
 }
 #endif                          /*  DOSEMU   */
 
-#if defined(DEBUG) || defined(FORSYS) || defined(_INIT) || defined(TEST)
+#if defined(DEBUG_NEED_PRINTF) || defined(FORSYS) || defined(_INIT) || defined(TEST)
 
 #ifndef FORSYS
 /* copied from bcc (Bruce's C compiler) stdarg.h */