Dos Box: -noconsole ?

Get DosBoxPortab.ini from the other/source folder and copy it to DosBoxPortable folder (alongside the launcher file)

Open it and add the -noconsole to the additional parameters.

@JohnTHaller

;Copyright (C) 2004-2008 John T. Haller

;Website: http://PortableApps.com/DosBoxPortable

;This software is OSI Certified Open Source Software.
;OSI Certified is a certification mark of the Open Source Initiative.

;This program is free software; you can redistribute it and/or
;modify it under the terms of the GNU General Public License
;as published by the Free Software Foundation; either version 2
;of the License, or (at your option) any later version.

;This program is distributed in the hope that it will be useful,
;but WITHOUT ANY WARRANTY; without even the implied warranty of
;MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;GNU General Public License for more details.

;You should have received a copy of the GNU General Public License
;along with this program; if not, write to the Free Software
;Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

!define NAME "DOSBoxPortable"
!define PORTABLEAPPNAME "DOSBox Portable"
!define APPNAME "DOSBox"
!define VER "1.5.6.0"
!define WEBSITE "PortableApps.com/DOSBoxPortable"

;=== Program Details
Name "${PORTABLEAPPNAME}"
OutFile "..\..\${NAME}.exe"
Caption "${PORTABLEAPPNAME} | PortableApps.com"
VIProductVersion "${VER}"
VIAddVersionKey ProductName "${PORTABLEAPPNAME}"
VIAddVersionKey Comments "Allows ${APPNAME} to be run from a removable drive.  For additional details, visit ${WEBSITE}"
VIAddVersionKey CompanyName "PortableApps.com"
VIAddVersionKey LegalCopyright "John T. Haller"
VIAddVersionKey FileDescription "${PORTABLEAPPNAME}"
VIAddVersionKey FileVersion "${VER}"
VIAddVersionKey ProductVersion "${VER}"
VIAddVersionKey InternalName "${PORTABLEAPPNAME}"
VIAddVersionKey LegalTrademarks "PortableApps.com is a Trademark of Rare Ideas, LLC."
VIAddVersionKey OriginalFilename "${NAME}.exe"
;VIAddVersionKey PrivateBuild ""
;VIAddVersionKey SpecialBuild ""

;=== Runtime Switches
CRCCheck On
WindowIcon Off
SilentInstall Silent
AutoCloseWindow True
RequestExecutionLevel user

; Best Compression
SetCompress Auto
SetCompressor /SOLID lzma
SetCompressorDictSize 32
SetDatablockOptimize On

;=== Includes
!include "FileFunc.nsh"
!insertmacro GetParameters
!include "MUI.nsh"

;=== Program Icon
Icon "..\..\App\AppInfo\appicon.ico"

;=== Icon & Stye ===
!define MUI_ICON "..\..\App\AppInfo\appicon.ico"

;=== Languages
!insertmacro MUI_LANGUAGE "English"

LangString LauncherFileNotFound ${LANG_ENGLISH} "${PORTABLEAPPNAME} cannot be started. You may wish to re-install to fix this issue. (ERROR: $MISSINGFILEORPATH could not be found)"
LangString LauncherAlreadyRunning ${LANG_ENGLISH} "Another instance of ${APPNAME} is already running. Please close other instances of ${APPNAME} before launching ${PORTABLEAPPNAME}."
LangString LauncherAskCopyLocal ${LANG_ENGLISH} "${PORTABLEAPPNAME} appears to be running from a location that is read-only. Would you like to temporarily copy it to the local hard drive and run it from there?$\n$\nPrivacy Note: If you say Yes, your personal data within ${PORTABLEAPPNAME} will be temporarily copied to a local drive. Although this copy of your data will be deleted when you close ${PORTABLEAPPNAME}, it may be possible for someone else to access your data later."
LangString LauncherNoReadOnly ${LANG_ENGLISH} "${PORTABLEAPPNAME} can not run directly from a read-only location and will now close."


Var DISABLESPLASHSCREEN
Var MISSINGFILEORPATH
Var EXECSTRING
Var ADDITIONALPARAMETERS

Section "Main"
	ReadINIStr $DISABLESPLASHSCREEN "$EXEDIR\${NAME}.ini" "${NAME}" "DisableSplashScreen"
        ReadINIStr $ADDITIONALPARAMETERS "$EXEDIR\${NAME}.ini" "${NAME}" "AdditionalParameters"

	IfFileExists "$EXEDIR\App\DOSBox\DOSBox.exe" SplashScreen
		;=== Program executable not where expected
		StrCpy $MISSINGFILEORPATH "$EXEDIR\App\DOSBox\DOSBox.exe"
		MessageBox MB_OK|MB_ICONEXCLAMATION `$(LauncherFileNotFound)`
		Abort
	
	SplashScreen:
		StrCmp $DISABLESPLASHSCREEN "true" SkipSplash
			;=== Show the splash screen before processing the files
			InitPluginsDir
			File /oname=$PLUGINSDIR\splash.jpg "${NAME}.jpg"
			newadvsplash::show /NOUNLOAD 1200 0 0 -1 /L $PLUGINSDIR\splash.jpg
			
	SkipSplash:
		IfFileExists '$EXEDIR\Data\settings\DOSBox.conf' GetParameters
			CreateDirectory '$EXEDIR\Data\settings'
			CopyFiles /SILENT '$EXEDIR\App\DefaultData\settings\DOSBox.conf' '$EXEDIR\Data\settings'

	GetParameters:
		${GetParameters} $0
		StrCmp "'$0'" "''" "" LaunchProgramParameters
			StrCpy $EXECSTRING `"$EXEDIR\App\DOSBox\DOSBox.exe" -conf "$EXEDIR\Data\settings\DOSBox.conf"`
			Goto LaunchNow
		
	LaunchProgramParameters:
		StrCpy $1 $0 5
		StrCmp $1 "-conf" LaunchProgramOnlyParameters
			StrCpy $EXECSTRING `"$EXEDIR\App\DOSBox\DOSBox.exe" -conf "$EXEDIR\Data\settings\DOSBox.conf" $0`
			Goto LaunchNow
	
	LaunchProgramOnlyParameters:
		StrCpy $EXECSTRING `"$EXEDIR\App\DOSBox\DOSBox.exe" $0`
	
	LaunchNow:
		SetOutPath "$EXEDIR\App\DOSBox"
		Exec '$EXECSTRING $ADDITIONALPARAMETERS'
		newadvsplash::stop /WAIT
SectionEnd

This is an updated launcher that uses
[DosBoxPortable]
AdditonalParameters=
To pass addtional commands.

Are you interested in me doing up a new package, updating to the latest installer, etc?

Do you realize that this parameter could also be called "portable mode"? When it's turned off, there's a price to pay - 2 files that DOSBOx writes to the active folder and never deletes them, which means soon enough your game folders would all contain these files.

If you've downloaded the portable version of DOSBox, despite the fact that DOSBox itself is portable in everything except putting itself in the start menu and in the uninstallations' list, obviously portability is important to you. But if you disable the console, you'd get a less portable version. That's a little ironic.