diff --git a/modflash/Makefile b/modflash/Makefile
new file mode 100644
index 0000000..7aa440f
--- /dev/null
+++ b/modflash/Makefile
@@ -0,0 +1,33 @@
+# Supported environments:
+#   * GNU/Linux
+#   * Windows NT (using MinGW/MSYS/Cygwin/WSL)
+
+ifeq ($(OS),Windows_NT)
+GENROM	= GenRom.exe
+ADDITEM	= AddItem.exe
+else
+GENROM	= GenRom
+ADDITEM	= AddItem
+endif
+
+.PHONY: all
+all: | FLASHempty.ZX1 $(GENROM) $(ADDITEM) ./addroms.sh ./addcores.sh
+	cp FLASHempty.ZX1 FLASH.ZX1
+	./addroms.sh
+	./addcores.sh
+
+ifneq ($(OS),Windows_NT)
+$(GENROM): GenRom.c
+	$(CC) $(CFLAGS) $< -o $@
+
+$(ADDITEM): AddItem.c
+	$(CC) $(CFLAGS) $< -o $@
+endif
+
+.PHONY: clean
+clean:
+ifeq ($(OS),Windows_NT)
+	rm -f FLASH.ZX1
+else
+	rm -f $(GENROM) $(ADDITEM) FLASH.ZX1
+endif
diff --git a/modflash/README.md b/modflash/README.md
new file mode 100644
index 0000000..420f931
--- /dev/null
+++ b/modflash/README.md
@@ -0,0 +1,25 @@
+# Target
+
+File `FLASH.ZX1` - .
+
+# Windows
+
+## Build
+
+```batch
+make.bat
+```
+
+# GNU/Linux
+
+## Build
+
+```bash
+make
+```
+
+## Clean
+
+```bash
+make clean
+```
diff --git a/modflash/addcores.sh b/modflash/addcores.sh
new file mode 100755
index 0000000..b696d56
--- /dev/null
+++ b/modflash/addcores.sh
@@ -0,0 +1,63 @@
+#!/bin/bash -e
+GENROM=./GenRom
+ADDITEM=./AddItem
+i=2
+
+Error() {
+	echo "ERROR: Exit status $1. Stopped." >&2
+	exit $1
+}
+
+AddCore() {
+	local f=${3%.*}.tap
+	echo "Adding core $i: \"$2\" ($3)..."
+	$GENROM $1 "$2" $3 $f || Error $?
+	$ADDITEM CORE$i $f || Error $?
+	rm -f $f
+	let i+=1
+}
+
+AddCore 0 "Apple 2"              cores/Apple2.ZX1
+AddCore 0 "Atari 2600"           cores/Atari2600.ZX1
+AddCore 0 "Atari 800 XL"         cores/Atari800XL.ZX1
+AddCore 0 "Acorn Atom"           cores/Atom.ZX1
+AddCore 0 "BBC Micro"            cores/BBCMicro.ZX1
+AddCore 0 "C16"                  cores/C16.ZX1
+AddCore 0 "C64"                  cores/C64.ZX1
+AddCore 0 "Test"                 cores/Test.ZX1
+AddCore 0 "ColecoVision"         cores/Coleco.ZX1
+AddCore 0 "CPC464"               cores/CPC464.ZX1
+AddCore 0 "CPC6128"              cores/CPC6128.ZX1
+AddCore 0 "Acorn Electron"       cores/Electron.ZX1
+AddCore 0 "Galaksija"            cores/Galaksija.zx1
+AddCore 0 "Jupiter Ace"          cores/JupAce.ZX1
+AddCore 0 "Spectrum Kyp"         cores/Kyp.ZX1
+AddCore 0 "MSX"                  cores/MSX.ZX1
+AddCore 0 "Nintendo NES"         cores/NES.ZX1
+AddCore 0 "Oric"                 cores/Oric.ZX1
+AddCore 0 "PC"                   cores/PC.ZX1
+AddCore 0 "PC2M"                 cores/PC2M.ZX1
+AddCore 0 "Sam Coupe"            cores/SamCoupe.ZX1
+AddCore 0 "Sega Master System"   cores/SMS.ZX1
+AddCore 0 "TBBlue"               cores/TBBlue.ZX1
+AddCore 0 "Vectrex"              cores/Vectrex.ZX1
+AddCore 0 "VIC-20"               cores/VIC20.ZX1
+AddCore 0 "Arcade Pacman"        cores/Arcades/pacman.ZX1
+AddCore 0 "Arcade Galaxian"      cores/Arcades/galaxian.ZX1
+AddCore 0 "Arcade Phoenix"       cores/Arcades/phoenix.ZX1
+AddCore 0 "Arcade The Glob"      cores/Arcades/theblob.ZX1
+AddCore 0 "Arcade Scramble"      cores/Arcades/scramble.ZX1
+AddCore 0 "Arcade Frogger"       cores/Arcades/frogger.ZX1
+AddCore 0 "Arcade Moon Cresta"   cores/Arcades/mooncresta.ZX1
+AddCore 0 "Arcade Jump Shot"     cores/Arcades/jumpshot.ZX1
+AddCore 0 "Arcade Amidar"        cores/Arcades/amidar.ZX1
+AddCore 0 "Arcade Black Hole"    cores/Arcades/blackhole.ZX1
+AddCore 0 "Arcade Crush Roller"  cores/Arcades/crush2.ZX1
+AddCore 0 "Arcade Galaga"        cores/Arcades/galaga.ZX1
+AddCore 0 "Arcade Gorkans"       cores/Arcades/gorkans.ZX1
+AddCore 0 "Arcade Lizard Wizard" cores/Arcades/lizwiz.ZX1
+AddCore 0 "Arcade Mr. Do"        cores/Arcades/mrdo.ZX1
+AddCore 0 "Arcade Ms. Pacman"    cores/Arcades/mspacman.ZX1
+AddCore 0 "Arcade Orbitron"      cores/Arcades/orbitron.ZX1
+AddCore 0 "Arcade Pac Miner"     cores/Arcades/pacminer.ZX1
+AddCore 0 "Arcade Pacman Plus"   cores/Arcades/pacplus.ZX1
diff --git a/modflash/addroms.sh b/modflash/addroms.sh
new file mode 100755
index 0000000..91840ef
--- /dev/null
+++ b/modflash/addroms.sh
@@ -0,0 +1,47 @@
+#!/bin/bash -e
+GENROM=./GenRom
+ADDITEM=./AddItem
+i=0
+
+Error() {
+	echo "ERROR: Exit status $1. Stopped." >&2
+	exit $1
+}
+AddROM() {
+	local n=`stat --printf "%s" $3`
+	local i1=$((i+n/16384-1))
+	local f=${3%.*}.tap
+	echo "Adding ROM in slots $i-$i1: \"$2\" ($3)..."
+	$GENROM $1 "$2" $3 $f || Error $?
+	$ADDITEM ROM $i $f || Error $?
+	rm -f $f
+	let i=i1+1
+}
+
+AddROM xdnlh17  "ZX Spectrum 48K"      roms/48.rom
+AddROM xtdnh1   "ZX Spectrum 128K EN"  roms/128en.rom
+AddROM xt       "ZX Spectrum +2A EN"   roms/plus3en41.rom
+AddROM xdlh     "48K Cargando Leches"  roms/leches.rom
+AddROM xdnlh17  "Inves Spectrum+"      roms/inves.rom
+AddROM xdnlh17  "Microdigital TK95"    roms/tk95.rom
+AddROM xdnlh17  "Looking Glass 1.07"   roms/lg18v07.rom
+AddROM xdnmlh17 "Timex Computer 2048"  roms/tc2048.rom
+AddROM xmh1     "Timex Computer 2068"  roms/tc2068.rom
+AddROM xpch1    "Pentagon 128"         roms/pentagon.rom
+AddROM xdlh17   "Pokemon"              roms/pokemon48.rom
+AddROM xdnlh17  "Gosh Wonderful v1.33" roms/gw03v33.rom
+AddROM xdh1     "SE Basic IV 4.0 Anya" roms/se.rom
+AddROM xtdnh1   "Derby+"               roms/derbyp.rom
+AddROM xt       "DivMMC +3e ES 1.43"   roms/plus3es143.rom
+AddROM xt       "Next +3e 1.53"        roms/next.rom
+AddROM xth1ru   "BBC Micro"            roms/BBCBasic.rom
+AddROM xth1ru   "Jupiter Ace"          roms/jupace.rom
+AddROM xth1ru   "ZX81"                 roms/zx81.rom
+AddROM xlh17ru  "Manic Miner (1983)"   roms/ManicMiner.rom
+AddROM xlh17ru  "Jet Set Willy (1984)" roms/JetSetWilly.rom
+AddROM xlh17ru  "Jet Pac (1983)"       roms/JetPac.rom
+AddROM xlh17ru  "Cookie (1983)"        roms/Cookie.rom
+AddROM xlh17ru  "Tranz Am (1983)"      roms/TranzAm.rom
+AddROM xlh17ru  "Planetoids (1983)"    roms/Planetoids.rom
+AddROM xlh17ru  "Space Raiders (1983)" roms/SpaceRaiders.rom
+AddROM xlh17ru  "Misco Jones (2013)"   roms/MiscoJones.rom