To produce debug version of DOS one need to run MKDEBUG.BAT script
You can change parameters like CPU type, messages language, etc.
inside this .BAT file. By default they are

 language - English
 CPU      - 386 or higher
 release  - 11

Apropriate SBIO.SYS file will be copied to the root of C: drive - debug version
assumes that boot drive is C: . To prevent interference between system under
debugging and standard one there are onother names for standard system files:

 SBIO.DEB - originaly SBIO.SYS
 CONFIG.DEB - originaly CONFIG.SYS

   You can also add SHELL = C:\SDOS\COMMAND.COM /P /C AUTODEB.BAT
   to skip parsing AUTOEXEC.BAT.


In success You will have file REL11\ENGLISH\386\DOS.EXE which is debug version.
Run DEBUG.BAT script. This script

   td386 -e200 -sm800 rel11\english\386\dos.exe

invokes Turbo debugger for 386 processor.
The SDOS will use space reserved by JUNK.ASM module - now approximately 320 K.
Startup segments defined in DRVSEG.ASM are

  for DEBUG version

OVERSEG		equ	2200h  512 bytes junk to correct DMA overrun
DRVSEG		equ	2220h  interrupt entries
LOWEST_SEG	equ	4500h  lowest segment to load "old" applications



 for release version

OVERSEG		equ	50h
DRVSEG		equ	70h
LOWEST_SEG	equ	0FFFh


Be carefully - these segments MUST BE IN DEBUG VERSION ADDRESS SPACE !
This may be violated when You load DOS.EXE too high.

During bootstrap SDOS will move itself down so You need to reset
RELOCATION FACTOR in Turbo Tebugger. One need to get current SDOS
command segment and subtract size of JUNK.ASM segments -
now this is CS - 5000h. But this is doesn't help You to get correct mapping
for relocatable parts of SDOS -

	CSFTMAN.ASM
	XMSUTIL.ASM
	XSFTMAN.ASM
	REBOOT.ASM
	STDCLOCK.ASM
	ATCLOCK.ASM
	ANSI.ASM
	KEYBOARD.ASM
	DISPLAY.ASM
	FCBIO.ASM
	LOADFX.ASM
	LOCK.ASM
	ZOMBI.ASM



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CONFIG.SYS debugging command.

You can debug SDOS during device loading by using CONFIG command

 DEBUGGER = ....

This command loads well behaviored .EXE module prior any device loading.
For example - QA.EXE - resident debugger by T. McQuaid.

----------------------------------------------------------------
Debugging DOS device drivers

The big problem of debugging device drivers is to prevent DOS desintegration
during your device installing. The Turbo dubugger also cannot opearate inside
DOS call. The proposed solution is to build debug version of SDOS and load
it with CONFIG.DEB where DEVICE=Your_device.



