diff --git a/.github/workflows/ci-build.yml b/.github/workflows/ci-build.yml
index 37e16a5..74348dd 100644
--- a/.github/workflows/ci-build.yml
+++ b/.github/workflows/ci-build.yml
@@ -23,10 +23,7 @@ jobs:
         submodules: recursive
 
     - name: Package install
-      run: |
-        sudo add-apt-repository ppa:tkchia/build-ia16
-        sudo apt update
-        sudo apt install gcc-ia16-elf libi86-ia16-elf nasm upx qemu-system-x86 mtools util-linux bash
+      run: ./ci_prereq.sh
 
     - name: build
       run: ./ci_build.sh
diff --git a/ci_build.sh b/ci_build.sh
index 2ddc95f..2edbf63 100755
--- a/ci_build.sh
+++ b/ci_build.sh
@@ -15,15 +15,20 @@ OWTAR=ow-snapshot.tar.xz
 
 # GCC
 mkdir _output/gcc
-git clean -x -d -f -e test -e _output -e _watcom -e $OWTAR
+git clean -x -d -f -e test -e _output -e _downloads -e _watcom -e $OWTAR
 make -C country clean
 make all COMPILER=gcc
 mv -n bin/KGC*.map bin/KGC*.sys _output/gcc/.
 mv -n bin/country.sys _output/gcc/.
 # GCC share
-(cd share && make clobber && env COMPILER=gcc ./build.sh)
-mv -n share/share.com _output/gcc/.
-mv -n share/share.map _output/gcc/.
+(
+  cd share
+  git submodule update --init --recursive
+  git clean -x -d -f
+  env COMPILER=gcc ./build.sh
+)
+mv -n share/src/share.com _output/gcc/.
+mv -n share/src/share.map _output/gcc/.
 
 # Watcom
 if [ ! -d _watcom ] ; then
@@ -37,10 +42,73 @@ export PATH=$BUILD_DIR/bin:$PATH:$BUILD_DIR/_watcom/binl64
 export WATCOM=$BUILD_DIR/_watcom
 
 mkdir _output/wc
-git clean -x -d -f -e test -e _output -e _watcom -e $OWTAR
+git clean -x -d -f -e test -e _output -e _downloads -e _watcom -e $OWTAR
 make -C country clean
 make all COMPILER=owlinux
 mv -n bin/KWC*.map bin/KWC*.sys _output/wc/.
 mv -n bin/country.sys _output/wc/.
 
+## DOS (GCC)
+#mkdir _output/gcc_dos
+#git clean -x -d -f -e test -e _output -e _downloads -e _watcom -e $OWTAR
+#{
+#  echo set COMPILER=GCC
+#  echo set MAKE=make
+#  echo set XCPU=386
+#  echo set XFAT=32
+#  echo set XNASM='C:\\devel\\nasm\\nasm'
+#  echo set OLDPATH=%PATH%
+#  echo set PATH='C:\\devel\\i16gnu\\bin;C:\\bin;%OLDPATH%'
+#} | unix2dos > config.bat
+
+#dosemu -td -q -K . -E "build.bat"
+
+# DOS (Watcom)
+mkdir _output/wc_dos
+git clean -x -d -f -e test -e _output -e _downloads -e _watcom -e $OWTAR
+{
+  echo set COMPILER=WATCOM
+  echo set WATCOM='C:\\devel\\watcomc'
+  echo set MAKE=wmake /ms
+  echo set XCPU=386
+  echo set XFAT=32
+  echo set XNASM='C:\\devel\\nasm\\nasm'
+  echo set OLDPATH=%PATH%
+  echo set PATH='C:\\devel\\watcomc\\binw;C:\\bin;%OLDPATH%'
+} | unix2dos > config.bat
+
+dosemu -td -q -K . -E "build.bat"
+mv -n bin/KWC*.map bin/KWC*.sys _output/wc_dos/.
+mv -n bin/country.sys _output/wc_dos/.
+
+
+# DOS (Turbo C 2.01)
+if [ -d ${HOME}/.dosemu/drive_c/tc201 ] ; then
+  mkdir _output/tc_dos
+  git clean -x -d -f -e test -e _output -e _downloads -e _watcom -e $OWTAR
+  {
+    echo set COMPILER=TC2
+    echo set TC2_BASE='C:\\tc201'
+    echo set MAKE=make
+    echo set XCPU=386
+    echo set XFAT=32
+    echo set XNASM=nasm
+    echo set OLDPATH=%PATH%
+    echo set PATH='%TC2_BASE%;C:\\devel\\nasm;C:\\bin;%OLDPATH%'
+  } | unix2dos > config.bat
+
+  dosemu -td -q -K . -E "build.bat lfn"
+  mv -n bin/KTC*.map bin/KTC*.sys _output/tc_dos/.
+  mv -n bin/country.sys _output/tc_dos/.
+  # TC share
+  (
+    cd share
+    git submodule update --init --recursive
+    git clean -x -d -f
+    env COMPILER=tcc2-emu ./build.sh
+  )
+  mv -n share/src/share.com _output/tc_dos/.
+  mv -n share/src/share.map _output/tc_dos/.
+fi
+
 echo done
diff --git a/ci_prereq.sh b/ci_prereq.sh
new file mode 100755
index 0000000..e5d2e80
--- /dev/null
+++ b/ci_prereq.sh
@@ -0,0 +1,63 @@
+#!/bin/sh
+
+set -e
+
+sudo add-apt-repository -y ppa:tkchia/build-ia16
+sudo add-apt-repository -y ppa:dosemu2/ppa
+sudo apt update
+
+# for cross building
+sudo apt install gcc-ia16-elf libi86-ia16-elf nasm upx qemu-system-x86 mtools util-linux bash
+
+# for building with DOS using an emulator
+sudo apt install dosemu2 dos2unix
+#    Perhaps later we should build using Freecom from published package
+
+mkdir -p _downloads
+cd _downloads
+
+HERE=$(pwd)
+
+#IBIBLIO_PATH='http://www.ibiblio.org/pub/micro/pc-stuff/freedos/files/distributions/1.2/repos/devel'
+IBIBLIO_PATH='https://www.ibiblio.org/pub/micro/pc-stuff/freedos/files/repositories/1.3/devel'
+
+#    get gnumake for DOS
+[ -f djgpp_mk.zip ] || wget --no-verbose ${IBIBLIO_PATH}/djgpp_mk.zip
+
+#    get nasm for DOS
+[ -f nasm.zip ] || wget --no-verbose ${IBIBLIO_PATH}/nasm.zip
+
+#    get upx for DOS
+[ -f upx.zip ] || wget --no-verbose ${IBIBLIO_PATH}/upx.zip
+
+#    grab ia16-gcc from ibiblio.org
+#[ -f i16gcc.zip ] || wget --no-verbose ${IBIBLIO_PATH}/i16gcc.zip
+#[ -f i16newli.zip ] || wget --no-verbose ${IBIBLIO_PATH}/i16newli.zip
+#[ -f i16butil.zip ] || wget --no-verbose ${IBIBLIO_PATH}/i16butil.zip
+#[ -f i16lbi86.zip ] || wget --no-verbose ${IBIBLIO_PATH}/i16lbi86.zip
+
+#   get watcom for DOS
+[ -f watcomc.zip ] || wget --no-verbose ${IBIBLIO_PATH}/watcomc.zip
+
+mkdir -p ${HOME}/.dosemu/drive_c
+cd ${HOME}/.dosemu/drive_c && (
+
+  mkdir -p bin
+  unzip -L -q ${HERE}/djgpp_mk.zip
+  cp -p devel/djgpp/bin/make.exe bin/.
+  unzip -L -q ${HERE}/upx.zip
+  cp -p devel/upx/upx.exe bin/.
+  echo PATH to make and upx binaries is 'c:/bin'
+
+  unzip -L -q ${HERE}/nasm.zip
+  echo PATH to nasm binary is 'c:/devel/nasm'
+
+#  unzip -L -q ${HERE}/i16gcc.zip
+#  unzip -L -q ${HERE}/i16newli.zip
+#  unzip -L -q ${HERE}/i16butil.zip
+#  unzip -L -q ${HERE}/i16lbi86.zip
+#  echo PATH to ia16 binaries is 'c:/devel/i16gnu/bin'
+
+  unzip -L -q ${HERE}/watcomc.zip
+  echo PATH to watcom binaries is 'c:/devel/watcomc/binw'
+)