diff --git a/build.bat b/build.bat
index d46de25..1c5caa9 100644
--- a/build.bat
+++ b/build.bat
@@ -6,8 +6,10 @@ if NOT "%1" == "/?" goto start
 echo ":-----------------------------------------------------------------------"
 echo ":- Syntax: BUILD [-r] [fat32|fat16] [msc|wc|tc|tcpp|bc] [86|186|386]    "
 echo ":-               [debug] [lfnapi] [/L #] [/D value] [list] [upx] [win]  "
+echo ":-               [com] [com# #]                                         "
 echo ":- option case is significant !!                                        "
 echo ":- Note: Open Watcom (wc) is the preferred compiler                     "
+echo ":- com does debug output on COM2, whereas com# 0 for COM1 ...           "
 echo ":-----------------------------------------------------------------------"
 goto end
 
@@ -56,6 +58,14 @@ if "%1" == "lfnapi" set ALLCFLAGS=%ALLCFLAGS% -DWITHLFNAPI
 if "%1" == "win"   set ALLCFLAGS=%ALLCFLAGS% -DWIN31SUPPORT
 if "%1" == "win"   set NASMFLAGS=%NASMFLAGS% -DWIN31SUPPORT
 
+if "%1" == "com"   set ALLCFLAGS=%ALLCFLAGS% -DDEBUG_PRINT_COMPORT
+if "%1" == "com"   set NASMFLAGS=%ALLCFLAGS% -DDEBUG_PRINT_COMPORT
+REM specify comport, default is COM2, 0=COM1, 1=COM2, 2=COM3
+if "%1" == "com#"   set ALLCFLAGS=%ALLCFLAGS% -DDEBUG_PRINT_COMPORT %2
+if "%1" == "com#"   set NASMFLAGS=%ALLCFLAGS% -DDEBUG_PRINT_COMPORT %2
+if "%1" == "com#"   shift
+if "%1" == "com#"   goto nextOption
+
 if "%1" == "list"  set NASMFLAGS=%NASMFLAGS% -l$*.lst
 
 if "%1" == "/L"    goto setLoadSeg
diff --git a/kernel/config.c b/kernel/config.c
index 27e8ac7..a26643e 100644
--- a/kernel/config.c
+++ b/kernel/config.c
@@ -31,10 +31,6 @@
 #include "init-mod.h"
 #include "dyndata.h"
 
-#ifdef VERSION_STRINGS
-static BYTE *RcsId =
-    "$Id: config.c 1705 2012-02-07 08:10:33Z perditionc $";
-#endif
 
 #ifdef DEBUG
 #define DebugPrintf(x) printf x
@@ -342,15 +338,9 @@ void PreConfig(void)
 {
   /* Initialize the base memory pointers                          */
 
-#ifdef DEBUG
-  {
-    printf("SDA located at 0x%p\n", internal_data);
-  }
-#endif
+  DebugPrintf(("SDA located at 0x%p\n", internal_data));
   /* Begin by initializing our system buffers                     */
-#ifdef DEBUG
-/*  printf("Preliminary %d buffers allocated at 0x%p\n", Config.cfgBuffers, buffers);*/
-#endif
+  /* DebugPrintf(("Preliminary %d buffers allocated at 0x%p\n", Config.cfgBuffers, buffers));*/
   
   LoL->sfthead = MK_FP(FP_SEG(LoL), 0xcc); /* &(LoL->firstsftt) */
   /* LoL->FCBp = (sfttbl FAR *)&FcbSft; */
@@ -362,18 +352,14 @@ void PreConfig(void)
 
   LoL->CDSp = KernelAlloc(sizeof(struct cds) * LoL->lastdrive, 'L', 0);
 
-#ifdef DEBUG
-/*  printf(" FCB table 0x%p\n",LoL->FCBp);*/
-  printf(" sft table 0x%p\n", LoL->sfthead);
-  printf(" CDS table 0x%p\n", LoL->CDSp);
-  printf(" DPB table 0x%p\n", LoL->DPBp);
-#endif
+/*  DebugPrintf((" FCB table 0x%p\n",LoL->FCBp));*/
+  DebugPrintf((" sft table 0x%p\n", LoL->sfthead));
+  DebugPrintf((" CDS table 0x%p\n", LoL->CDSp));
+  DebugPrintf((" DPB table 0x%p\n", LoL->DPBp));
 
   /* Done.  Now initialize the MCB structure                      */
   /* This next line is 8086 and 80x86 real mode specific          */
-#ifdef DEBUG
-  printf("Preliminary  allocation completed: top at %p\n", lpTop);
-#endif
+  DebugPrintf(("Preliminary  allocation completed: top at %p\n", lpTop));
 }
 
 /* Do second pass initialization: near allocation and MCBs              */
@@ -443,9 +429,7 @@ void PostConfig(void)
 
   /* Begin by initializing our system buffers                     */
   /* dma_scratch = (BYTE FAR *) KernelAllocDma(BUFFERSIZE); */
-#ifdef DEBUG
-  /* printf("DMA scratchpad allocated at 0x%p\n", dma_scratch); */
-#endif
+  /* DebugPrintf(("DMA scratchpad allocated at 0x%p\n", dma_scratch)); */
 
   config_init_buffers(Config.cfgBuffers);
 
@@ -462,12 +446,11 @@ void PostConfig(void)
 
   LoL->CDSp = KernelAlloc(sizeof(struct cds) * LoL->lastdrive, 'L', Config.cfgLastdriveHigh);
 
-#ifdef DEBUG
-/*  printf(" FCB table 0x%p\n",LoL->FCBp);*/
-  printf(" sft table 0x%p\n", LoL->sfthead->sftt_next);
-  printf(" CDS table 0x%p\n", LoL->CDSp);
-  printf(" DPB table 0x%p\n", LoL->DPBp);
-#endif
+/*  DebugPrintf((" FCB table 0x%p\n",LoL->FCBp));*/
+  DebugPrintf((" sft table 0x%p\n", LoL->sfthead->sftt_next));
+  DebugPrintf((" CDS table 0x%p\n", LoL->CDSp));
+  DebugPrintf((" DPB table 0x%p\n", LoL->DPBp));
+
   if (Config.cfgStacks)
   {
     VOID FAR *stackBase =
@@ -1845,9 +1828,7 @@ STATIC BOOL LoadDevice(BYTE * pLine, char FAR *top, COUNT mode)
   /* The device driver is paragraph aligned.                      */
   eb.load.reloc = eb.load.load_seg = base;
 
-#ifdef DEBUG
-  printf("Loading device driver %s at segment %04x\n", szBuf, base);
-#endif
+  DebugPrintf(("Loading device driver %s at segment %04x\n", szBuf, base));
 
   if ((result = init_DosExec(3, &eb, szBuf)) != SUCCESS)
   {
diff --git a/kernel/dosfns.c b/kernel/dosfns.c
index 3d902ee..f1479aa 100644
--- a/kernel/dosfns.c
+++ b/kernel/dosfns.c
@@ -34,6 +34,7 @@ static BYTE *dosfnsRcsId =
 #endif
 
 #include "globals.h"
+#include "debug.h"
 
 /* /// Added for SHARE.  - Ron Cemer */
 
diff --git a/kernel/error.c b/kernel/error.c
index da7d382..035312b 100644
--- a/kernel/error.c
+++ b/kernel/error.c
@@ -27,24 +27,20 @@
 /****************************************************************/
 
 #include "portab.h"
-
-#ifdef VERSION_STRINGS
-static BYTE *errorRcsId =
-    "$Id: error.c 709 2003-09-24 19:34:11Z bartoldeman $";
-#endif
-
 #include "globals.h"
+#include "debug.h"
+
 
 #ifdef DEBUG
 /* error registers                                      */
 VOID dump(void)
 {
-  printf("Register Dump [AH = %02x CS:IP = %04x:%04x FLAGS = %04x]\n",
-         error_regs.AH, error_regs.CS, error_regs.IP, error_regs.FLAGS);
-  printf("AX:%04x BX:%04x CX:%04x DX:%04x\n",
-         error_regs.AX, error_regs.BX, error_regs.CX, error_regs.DX);
-  printf("SI:%04x DI:%04x DS:%04x ES:%04x\n",
-         error_regs.SI, error_regs.DI, error_regs.DS, error_regs.ES);
+  DebugPrintf(("Register Dump [AH = %02x CS:IP = %04x:%04x FLAGS = %04x]\n",
+         error_regs.AH, error_regs.CS, error_regs.IP, error_regs.FLAGS));
+  DebugPrintf(("AX:%04x BX:%04x CX:%04x DX:%04x\n",
+         error_regs.AX, error_regs.BX, error_regs.CX, error_regs.DX));
+  DebugPrintf(("SI:%04x DI:%04x DS:%04x ES:%04x\n",
+         error_regs.SI, error_regs.DI, error_regs.DS, error_regs.ES));
 }
 #endif
 
diff --git a/kernel/fatfs.c b/kernel/fatfs.c
index a3e53de..1be8726 100644
--- a/kernel/fatfs.c
+++ b/kernel/fatfs.c
@@ -29,10 +29,8 @@
 
 #include "portab.h"
 #include "globals.h"
+#include "debug.h"
 
-#ifdef VERSION_STRINGS
-BYTE *RcsId = "$Id: fatfs.c 1632 2011-06-13 16:29:14Z bartoldeman $";
-#endif
 
 /*                                                                      */
 /*      function prototypes                                             */
diff --git a/kernel/inthndlr.c b/kernel/inthndlr.c
index 40cb386..ce3fc5d 100644
--- a/kernel/inthndlr.c
+++ b/kernel/inthndlr.c
@@ -442,7 +442,7 @@ dispatch:
   if (bDumpRegs)
   {
     fmemcpy(&error_regs, user_r, sizeof(iregs));
-    printf("System call (21h): %02x\n", user_r->AX);
+    DebugPrintf(("System call (21h): %02x\n", user_r->AX));
     dump_regs = TRUE;
     dump();
   }
diff --git a/kernel/main.c b/kernel/main.c
index c8afb93..33e7841 100644
--- a/kernel/main.c
+++ b/kernel/main.c
@@ -32,10 +32,6 @@
 #include "dyndata.h"
 #include "debug.h"
 
-#ifdef VERSION_STRINGS
-static BYTE *mainRcsId =
-    "$Id: main.c 1699 2012-01-16 20:45:44Z perditionc $";
-#endif
 
 static char copyright[] =
     "(C) Copyright 1995-2023 Pasquale J. Villani and The FreeDOS Project.\n"