The full signal chain, from your hand to the game
Every cable in an aim-assist build, in order: mouse to input device, input device to game PC and card to second PC, plus exactly where the second PC's commands enter the chain.
Short answer
The mouse goes into the input device's host port, the device into the game PC, and the second PC into the device's control port. Never cable the game PC directly to the second PC: the only link between them should be a mouse.
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How the signal chain works
Your hand moves a mouse, and that mouse is plugged into the input device rather than into the game PC. The input device forwards every movement and click and presents itself to the game PC as a single ordinary USB mouse. Separately, the DMA card in the game PC streams physical memory over its own USB cable to the second PC, where the software works out where the targets are. When that software wants the cursor moved, it sends a small command to the input device over a third link. The input device injects that movement into the same mouse stream your hand is already using, so the game PC receives one mouse, on one port, doing all of it.
The five parts of the chain
The chain has five parts, and each one has exactly one job. If you can say what each job is, you can debug this build.
- 1. Physical mouse
- Your actual hand input. Plugs into the input device's host port and nowhere else
- 2. Input device
- KMBox, MAKCU, Teensy or Arduino. Merges your hand and the second PC's commands into one HID stream
- 3. Game PC
- Runs the game. Holds the DMA card in a PCIe or M.2 slot. Sees one mouse and one anonymous PCIe device, and nothing else
- 4. DMA card
- Reads the game PC's physical memory and streams it out of its data port over USB
- 5. Second PC
- Reads the memory stream, decides what to do, and sends movement commands to the input device. Never touches the game PC in any other way
How to wire the build, step by step
Follow this sequence with everything powered off. The order matters, because if you wire the control link before the HID link, your first test will not show which half of the chain is at fault.
- Power down both machines. Seat the DMA card in a free PCIe or M.2 slot in the game PC and screw the bracket down
- Run a USB 3 data cable from the card's DATA port, not its flashing port, to a rear USB 3 port on the SECOND PC rather than a front-panel header
- Plug your physical mouse, or your wireless mouse's dongle, into the input device's HOST port
- Run a cable from the input device's HID port directly to a rear USB port on the GAME PC, with no hub in the path
- Run the control cable from the input device to the SECOND PC. This is a USB serial connection for KMBox B+, MAKCU, Teensy or Arduino, or the network-side cable for a KMBox Net
- Boot the GAME PC first, let it reach the desktop, and confirm that your hand moves the cursor. Do not go further until it does
- Boot the SECOND PC, then install or confirm the FTDI driver for the card and the serial or network driver for the input device
- Open the cheat, connect to the card and then to the input device. Run the device's movement test and watch the game PC's cursor move on its own
- If you want the overlay on the main monitor, the fuser goes in the video path between the game PC and the display. It is not part of the input chain at all
What each cable carries
The four cables carry four completely different kinds of traffic, and confusing them is the root of most wiring mistakes.
| Link | Direction | Carries | What the game PC thinks it is |
|---|---|---|---|
| Mouse to input device | One way, into the device | Your hand: HID reports for movement, buttons and wheel | Nothing. This cable is on the far side of the input device and the game PC never sees it |
| Input device to game PC | One way, into the game PC | A single merged HID mouse stream: your hand plus injected movement | A USB mouse, on a mouse port, behaving like a mouse |
| DMA card to second PC | Mostly out of the game PC | Physical memory, streamed over the card's USB data bridge | Nothing. To the game PC the card is a PCIe device, and its USB side is not visible to the operating system |
| Input device to second PC | One way, into the device | Small movement and click commands, over serial or IP | Nothing. This link terminates at the input device and never reaches the game PC |
Two of the four cables physically bridge the two machines, and neither of them presents the second PC to the game PC as a computer. That separation is the design and its whole purpose.
Where the second PC's commands enter the chain
They enter inside the input device, which is the only place they can enter. The device has a mouse on one side and the game PC on the other, and it is already forwarding a report stream between them. A movement command from the second PC becomes an extra report in that same stream, or an adjustment to the next one. It uses the same endpoint and the same descriptor as your hand's reports. No second device, second interface or separate channel arrives at the game PC. The merge happens one hop before the game PC, and everything downstream of it is indistinguishable in kind from what your hand does.
Warning
Why the game PC must never see the second PC directly
This rule is often stated carelessly, so it helps to be precise about what it means. Two cables do physically join the machines (the card's data cable and the input device's two ends), but neither presents your cheat machine to the game PC as a machine. The card is an anonymous PCIe device whose USB side the game PC's operating system cannot see at all, and the input device is a mouse. What must not exist is anything that makes the two computers peers. That rules out an Ethernet cable or shared switch segment between them, a remote desktop or VNC session, and file sharing or a mapped drive. It also rules out a cloud sync folder that both write to. The same applies to a shared account logged in on both, and to a KVM or shared peripheral that both enumerate. Each of these leaves an artefact on the gaming machine, such as a route, a share, a session or a device history. Each one points to a second computer sitting beside it and doing something. The chain you have built is designed so that nothing on the game PC knows the second PC exists. Do not undo that with a network cable just because copying a config file was convenient. Do not run the cheat's own updater on the game PC because the download was faster there.
How to test the chain one link at a time
Run this once after building, and again whenever something breaks. Each step tests exactly one link, so the first failure tells you where to work.
- Game PC only, powered on: move your own mouse. If the cursor moves, the mouse, the input device's passthrough and the HID link are all good
- Game PC, Device Manager: check that exactly one mouse is listed for your setup and that the card appears as a PCIe device with no warning triangle
- Second PC, Device Manager: check that the card's FTDI device is present and that the input device appears as a COM port or a network adapter
- Second PC: run the card's read-speed tool. A healthy figure proves the memory link independently of everything else
- Second PC: ping the input device if it is a network model, or open its port if it is serial, and do this before you open the cheat
- Second PC, cheat: connect to the card, then run the input device's movement test and watch the game PC's cursor move without your hand on the mouse
- Only now enable any aim feature. If you skipped one of the earlier steps, a problem at this point will look like a cheat bug when it is not one
Final wiring checklist
- The physical mouse is plugged into the input device only, never also into the game PC
- The input device's HID cable goes to a rear game PC port with no hub in the path
- The DMA card's cable is in its data port, not its flashing port
- The card's cable reaches a rear USB 3 port on the second PC, with no hub or dock
- There is no Ethernet, remote desktop, file share or sync folder connecting the two machines
- Nothing cheat-related is installed on the game PC, including updaters and archives
- The game PC's Device Manager shows one mouse, and nothing that names your input device's manufacturer oddly
- The fuser, if you use one, is in the video path and touches nothing in this chain
Common wiring questions
Can the input device's control cable go to the game PC instead?
No, because that defeats the design. The commands come from the second PC because that is where the software runs. A control link to the game PC would put a second interface from the same gadget on the machine you are trying to keep unremarkable.
Can I share one keyboard and mouse between both machines with a KVM?
Not for the mouse that goes through the input device, and think carefully before doing it for the keyboard. A KVM is a device both machines enumerate, which is exactly the kind of shared artefact this chain is built to avoid, so use a second cheap keyboard on the second PC.
Does the second PC need internet?
Usually yes, for the cheat's own authentication and updates. Give it its own internet access through a separate Ethernet or Wi-Fi connection to your router, and do not share the game PC's connection.
Where does a fuser fit in this diagram?
It is not part of the input chain. A fuser sits in the video path and combines the game PC's output with the second PC's overlay into what your monitor shows. It has no involvement in mouse input and cannot move a cursor.
Do I need the input device at all if I only want a radar?
No. A radar or an ESP overlay is read-only and needs only the card, the second PC and a screen. The input device is the only part of the stack that acts on the game, so you add it when you decide you want that.
Does this wiring make the setup undetectable?
No. It removes the easy software signals from the gaming machine and keeps the two computers from being visibly related to each other. It does not remove the PCIe device, the input device's USB identity or the shape of your aim, which remain the real exposure, and no cable routing changes them.
Sources
This is bench wiring: the cable order and the five nodes come from building these setups, not from a published document.
Read next
- KMBox Net, KMBox B+, MAKCU, Teensy or Arduino: which input device to buy
- The cursor will not move: how to fix the input layer
- USB descriptors, VID/PID and what descriptor cloning means
- Teensy 4.1 as a DMA input device
- How to set up a second PC for DMA
- What are DMA cheats and how do they work
- Fuser and capture display path
- Arduino Leonardo and a USB Host Shield
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