Patch for the Macromedia Director runtime used by ZeroZone and other games so it can run on systems with > 2 GiB of RAM.

macromedia-director-patch-for-zero-zone.sh

#!/bin/bash
# Patch for the Macromedia Director runtime used by ZeroZone so it can run on systems with > 2 GiB of RAM.
#
# This patch has been confirmed to work with:
#   - The Italian version of ZeroZone, where the runtime is located at ./ZZnet/ZZnet.exe
#   - The English version of ZeroZone, where the runtime is located at ./GalaxyNet.exe
#
# The same patch may also apply to other games built with the same Macromedia Director runtime.
# There are several version of the runtime, see https://wiki.scummvm.org/index.php?title=Director/Versions
# This patch only applies to versions equal or similar to the one used in ZeroZone.
# Read the technical notes below before attempting to use it on other executables.
# If it does work or you find a different location for another version please consider opening a PR.
#
# ---------------------------------------------------------------------------
# Technical notes
# ---------------------------------------------------------------------------
# The Macromedia Director runtime requires at least 3 MB of memory to start.
#
# The runtime calls GlobalMemoryStatus and adds together
#   dwAvailPageFile + dwAvailPhys
# and then casts the result to a 32-bit signed integer.
#
# On systems with 2+ GiB of RAM this addition overflows the 32-bit signed
# range and becomes negative. The subsequent comparison against the 3 MB
# threshold therefore always fails, and the program refuses to start even
# though plenty of memory is available.
#
# This patch modifies the conditional check at offset 0x000B54C8 so that the
# memory test is unconditionally treated as “passed”, allowing the runtime
# to start normally on modern systems.
#
# An alternative approach would be to hook or patch GlobalMemoryStatus so
# that it reports less than 2 GiB of available memory, but this script keeps
# things simple and only adjusts the in-game check.
#

set -e

# Detect target executable
target=""

if [ -f "ZZnet/ZZnet.exe" ]; then
    target="ZZnet/ZZnet.exe"
    echo "✓ Detected Italian ZeroZone runtime at '${target}'."
elif [ -f "GalaxyNet.exe" ]; then
    target="GalaxyNet.exe"
    echo "✓ Detected English ZeroZone runtime at '${target}'."
else
    echo "✗ No supported executable found."
    echo "  Expected either './ZZnet/ZZnet.exe' or './GalaxyNet.exe' in the current directory."
    echo "  Nothing was patched."
    exit 1
fi

# Check that xxd is available
if ! command -v xxd >/dev/null 2>&1; then
    echo "✗ The 'xxd' utility is not installed. Please install it and run this script again."
    exit 1
fi

# Create a backup before patching
backup="${target}.bak"

if [ ! -f "${backup}" ]; then
    cp "${target}" "${backup}"
    echo "✓ Created backup: '${backup}'."
else
    echo "ℹ Backup '${backup}' already exists; it will not be overwritten."
fi

# Apply the patch
echo "→ Applying memory check patch to '${target}'..."
echo "000b54c8: eb" | xxd -r - "${target}"
echo "✓ Patch successfully applied to '${target}'."
echo "All done. You can now run the game on systems with more than 2 GiB of RAM."