Prepare a bootable HighAsCG USB stick on Windows: install Ventoy while reserving space at the end of the disk, create the operator exFAT partition in that space with Disk Management, copy the ISO onto the Ventoy volume, copy the starter folder layout, then boot the playout machine from the stick.
Time: ~25 minutes · USB size: 32 GiB is enough — Ventoy holds the ISOs, the reserved tail holds operator data
You need: Windows 10 version 1703 or newer (earlier Windows only exposes the first partition of a removable drive, which hides the operator volume).
Why Ventoy and not Etcher? Ventoy keeps the ISO as a file, so updating a machine later means dropping a new ISO next to the old one instead of reflashing the whole stick — and the previous build stays as a fallback. The old Etcher flow and its fixed 6 GiB offset rule are retired; ignore any guide that still mentions them.
Three partitions. Ventoy creates the first two; you create the third.
| # | Label | Size | Purpose |
|---|---|---|---|
| 1 | Ventoy |
rest of the disk | exFAT — the ISO files live here |
| 2 | VTOYEFI |
32 MiB | Ventoy’s boot partition — never touch it |
| 3 | HIGHASCGEXF |
the space you reserved | exFAT — configs, media, server updates. Must be exactly this label (11 characters) |
On boot, the playout machine mounts HIGHASCGEXF at /home/casparcg/exfat, applies any server drop in drop-update/, syncs configs/, and starts the operator UI at http://<playout-ip>:4200/ (WO-498: the nginx port-80 proxy was removed — connect with the port).
Do not put operator data on the Ventoy partition. While the machine is booted from a stick, Ventoy holds that partition open for the ISO it is streaming, and Linux cannot mount it. Operator data has to be its own partition — that is the whole reason for reserving space in step 2.
Always use the current build — filenames change with each release.
| Method | Link |
|---|---|
| Browser (recommended) | https://highascg.dpdns.org/ — click DOWNLOAD BOOTABLE ISO |
| Direct URL (auto-latest) | Read download_url from release.json |
PowerShell:
$release = Invoke-RestMethod https://highascg.dpdns.org/release.json
Invoke-WebRequest -Uri $release.download_url -OutFile highascg-latest.iso
Current builds are ~3.7 GiB. Trust release.json, not a fixed filename.
Copying an ISO you built in house? Wait for
build-highascg-egg.shto printDone. ISO:before copying it anywhere. The file appears minutes earlier — its name carries the produce time, not the finish time — and the build keeps re-packing it afterwards. Copying inside that window produces a stick that reaches the GRUB menu and then dies with “invalid magic number / you need to load the kernel first”. The build writes<iso>.sha256last, so the sidecar existing is the signal the ISO is finished.
Download Ventoy from https://www.ventoy.net/ and unzip it. No installation needed — run the executable from the folder.
Installing Ventoy erases the entire stick. Check the device size and model before you click.
Ventoy2Disk.exe.When it finishes, Explorer shows a Ventoy drive, and Disk Management will show the 32 MiB VTOYEFI partition plus unallocated space at the end — that last part is what step 3 fills.
HIGHASCGEXF)Use Disk Management — the standard Windows disk utility. Press Win + X → Disk Management (or run diskmgmt.msc).
Disk Management is safe here, and this is a change from older HighAsCG guides. Those forbade it because a raw-flashed ISO left free space Windows misread, so a new partition landed inside the boot image. Ventoy reserves the space itself, at the end of the disk, so the unallocated block you see is the only free region and there is no offset to get right.
Ventoy and 32 MB partitions next to the unallocated block. Getting the wrong disk destroys it.HIGHASCGEXF — exactly this, all capitals, no spacesThe label is not cosmetic. The playout machine looks for a volume labelled exactly
HIGHASCGEXF(exFAT allows at most 11 characters). Anything else and the stick boots but no operator data is applied. If you mistype it, right-click the volume in Explorer → Rename.
Copy the .iso to the root of the Ventoy drive — not into a subfolder, and not onto HIGHASCGEXF. Ventoy lists every ISO it finds there, so you can keep the previous build alongside the new one and choose at boot.
Then eject properly. Use Safely Remove Hardware (or right-click the drive → Eject) and wait for the confirmation. A copy that looks finished in Explorer can still be sitting in RAM; pulling the stick early leaves a file of exactly the right size full of stale bytes, and the machine boots to GRUB and then fails on the kernel.
Verify before you trust it — matching size proves nothing, only the hash does:
Get-FileHash .\highascg-latest.iso -Algorithm SHA256
Get-FileHash E:\highascg-latest.iso -Algorithm SHA256 # E: = the Ventoy drive
The two hashes must be identical. If they differ, delete the copy on the stick, copy again, eject properly, and re-check.
HIGHASCGEXFDownload HIGHASCGEXF-starter-layout.zip from this repo.
Unzip directly onto the HIGHASCGEXF volume root — not inside an extra folder, and not onto the Ventoy drive. Adjust F: to the HIGHASCGEXF drive letter:
Expand-Archive -Path HIGHASCGEXF-starter-layout.zip -DestinationPath F:\ -Force
Expected top-level folders after unzip:
HIGHASCGEXF/
configs/ ← factory settings + starter show
drop-config/
drop-update/ ← put highascg-server_*.tar.gz here later
drop-update/applied/
media/
network/ ← operator IP file network.conf
projects/
snapshots/rear-panels/
templates/
.private/ ← per-machine pairing data (hidden folder)
decklink/ ← optional DeckLink vendor debs
README.txt
Eject the stick safely when copying finishes.
Optional later: extract a GitHub server release (
highascg-server_*.tar.gz) intodrop-update/sodrop-update/package.jsonexists. The starter zip alone is enough for a first boot test with the embedded ISO server tree.
The public ISO does not ship Blackmagic Desktop Video. If the playout machine has a DeckLink card, copy vendor packages into decklink/ on HIGHASCGEXF:
HIGHASCGEXF/decklink/
desktopvideo_<version>_amd64.deb ← required for Caspar decklink I/O
desktopvideo-gui_<version>_amd64.deb ← optional (Setup / Updater GUI)
Download Desktop Video for Linux, extract the tarball, and copy from deb/x86_64/. desktopvideo alone is enough for playout; without the GUI package, Settings → Desktop Video Setup / Updater simply report GUI not installed. On boot, HighAsCG installs from decklink/ when needed (highascg-decklink-install.service).
F2, F12, Del, Esc at the manufacturer logo)F12 on many boards)After boot:
http://127.0.0.1/ on the machine, or http://<playout-ip>/ from the LANfindmnt /home/casparcg/exfat — it should show the third partition| Step | Done when |
|---|---|
| ISO downloaded | Size matches release.json |
| Ventoy installed | Explorer shows a Ventoy drive; Disk Management shows unallocated space at the end |
| exFAT created | Explorer shows HIGHASCGEXF with gigabytes free |
| ISO copied | Get-FileHash matches on both sides, after a safe eject |
| Starter zip copied | configs/, drop-update/, media/, … at the HIGHASCGEXF root |
| BIOS | Secure Boot off, USB boot on |
| Live boot | Ventoy menu → GRUB → playout starts; :4200 responds |
| Problem | Fix |
|---|---|
| “invalid magic number / you need to load the kernel first” after the GRUB menu | The ISO on the stick is corrupt — almost always copied while the build was still writing it, or the stick was pulled before the copy flushed. Re-copy, eject safely, and compare Get-FileHash (step 4) |
| No unallocated space in Disk Management | You skipped Preserve some space at the end of the disk. Re-run the Ventoy installer with it set — this erases the stick |
| Ventoy drive nearly full | Delete the oldest ISO from the Ventoy drive — each build is ~3.7 GiB |
| Explorer only shows one USB drive | Windows older than 10 version 1703 exposes only the first partition of a removable drive. Update Windows, or use a newer machine to prepare the stick |
| Ventoy menu appears but no HighAsCG entry | The ISO is not at the root of the Ventoy drive, or the copy never finished |
| Stick boots but no exFAT sync | The label must be exactly HIGHASCGEXF, and it must be the third partition — not the Ventoy one |
| New Simple Volume… greyed out | You right-clicked an existing partition instead of the Unallocated block, or you picked the wrong disk |
| Secure Boot error / no NVIDIA | Disable Secure Boot in BIOS |
| Updating to a new build | Copy the new ISO next to the old one and pick it in the Ventoy menu — no reflash, and the previous build stays as a fallback |
| Topic | Document |
|---|---|
| Stick contents / server drops | ../tools/eggs/live-usb/MANUAL_STICK_WINDOWS_MACOS.md |
| exFAT vs ISO contents | WO47_ISO_VS_EXFAT.md |
| Bridge disk + USB roles | BRIDGE_DISK_AND_USB_EXFAT.md |
| Server drops on the stick | EXFAT_SERVER_UPDATE.md |
| Building the ISO in house | ../tools/eggs/live-usb/BUILD_AND_FLASH.md |