Compatibility by device type
GL.iNet's FAQ says its KVMs control devices with HDMI output and USB input, and gives notebooks, workstations and single-board computers as examples [1]. The harder questions are whether you can see firmware screens and whether you can control power. Both depend on the device type.
| Device | Video into the KVM | Firmware and boot screens | Remote power |
|---|---|---|---|
| Desktop PC | HDMI to Comet Pro's HD IN [4] | Yes, if the KVM is on the primary output; DisplayPort may be favored at boot [2] | ATX board on the front-panel header [8] |
| Windows laptop with HDMI | HDMI; some laptops need an Fn key, often F5, to start output [5] | Usually not: the built-in screen is primary [2] | No ATX header; Wake-on-LAN or Fingerbot [1][3] |
| Laptop with USB-C video only | Comet Q accepts USB-C with DisplayPort Alt Mode [1]; HDMI KVMs need an adapter | Same primary-display limit [2] | Comet Q does not work with the ATX board or Fingerbot [1] |
| Intel Mac | HDMI or USB-C as above; PiKVM lists a known issue with Apple TB/USB-C to HDMI [5] | Startup keys such as Option and Command-R must be held at startup [7] | No ATX headers [6]; Wake-on-LAN if supported, or Fingerbot [1][3] |
| Apple silicon Mac | As above [1][5] | No startup key combinations; hold the power button [7] | No ATX headers [6]; Wake-on-LAN if supported, or Fingerbot [1][3]; only a held button press reaches startup options [7] |
Video: the primary-display problem
GL.iNet's explanation is the key fact for laptop owners. The BIOS usually outputs only to the primary monitor, and on a laptop the built-in screen is primary, so an external KVM cannot capture the BIOS [2]. Its desktop fix, a 1-to-2 HDMI splitter on the primary output, does not help when the primary output is the internal panel [2]. Once the OS is running and has mirrored or extended to the external display, the KVM sees the desktop normally.
Some laptops send nothing over HDMI until you switch the output, usually with Fn and an F-key such as F5 [5]. Set that up at home and confirm the KVM shows a picture after a reboot, before you rely on it away from home.
Keyboard and mouse on a Mac
A KVM types as a USB keyboard, and Macs have a few quirks with that. GL.iNet's console includes Swap Command and Ctrl for MacOS, so your local Ctrl shortcuts land as Command on the Mac [3]. PiKVM's FAQ says macOS may need you to allow new accessories to connect. It also says that if a USB-C to USB-C cable does not give working keyboard and mouse, you should use the included USB-C to USB-A cable with a USB-A to USB-C adapter [5].
For Intel Macs, Apple's startup key list includes Command-R for macOS Recovery, Option for Startup Manager, Shift for safe mode and D for Apple Diagnostics. Apple adds that PC keyboards, such as those with a Windows logo, may not work for these combinations. It says to wait a few seconds after startup begins so the keyboard is recognized, and that a firmware password can block some combinations [7]. Test each combination you need through the KVM at home, since a KVM is an emulated keyboard rather than an Apple one.
Apple silicon: startup options need the power button
Apple says Apple silicon Macs have no startup key combinations. You press and hold the power button as the Mac starts, and release it when the startup options screen appears with your disks and an Options gear [7]. Keyboard emulation cannot reach that screen. Startup options are also where you would pick another disk, and none of the GL.iNet, PiKVM or Apple pages cited here describe booting an Apple silicon Mac from KVM virtual media. Do not plan a remote macOS reinstall around it.
GL.iNet's Fingerbot is a small device that presses a physical button, with Time settings of 0.5 s, 3 s and 8 s and two strength levels [3]. Apple's instruction is to keep holding until the startup options screen appears [7]. Neither Apple nor GL.iNet says whether a fixed 8-second press is long enough on a given Mac, so treat this as something to test in person first.
Staying awake and powering on without ATX headers
ATX power boards wire into a desktop motherboard's front-panel header. GL.iNet's board documents 10-1, 20-5 and 20-8 pin panel layouts [8]. PiKVM states that Apple Macs lack the needed ATX headers and that its board is only for PC servers and desktops [6]. Laptops are not covered by either vendor's ATX documentation [6][8]. That leaves three tools.
| Method | What it does | Limits per docs |
|---|---|---|
| Mouse Jiggle | Prevents the controlled device sleeping from prolonged inactivity [1][3] | Keeps it awake; cannot wake it or power it on |
| Wake-on-LAN | Powers on or wakes a device from a low-power state over the network [3] | The device and its network adapter must support it |
| Fingerbot (GL-FGB-01) | Physically presses a button; 0.5 s, 3 s or 8 s; light or firm [3] | Sold separately; does not work with Comet Q [1] |
| ATX board (GL-ATXPC) | Simulates the case power button [8] | Desktop front-panel headers only; not Macs [6][8] |
Test at home before you leave
Every limit above is easiest to discover at your desk. Run this list with the laptop or Mac set up exactly as you will leave it.
- Reboot the target and confirm the KVM shows video without touching the laptop; if not, set the output switch or display mode [5][2].
- Check whether you can see the boot screen at all. On most laptops, expect OS-only control [2].
- On a Mac, approve the KVM as an accessory if asked, and try the cable fallback if input does not work [5].
- Try every startup key you might need through the KVM, not on the built-in keyboard [7].
- Turn on Mouse Jiggle, or set the OS sleep settings, and leave the session idle long enough to prove the target stays awake [1].
- Shut the target down and bring it back with Wake-on-LAN or the Fingerbot before you rely on either [1][3].
Questions before you decide
Why does my laptop show its desktop on the KVM but not the BIOS?
GL.iNet explains that the BIOS usually outputs only to the primary monitor, and on a laptop the built-in screen is primary, so an external KVM cannot capture the BIOS. Plan on OS-level work only, unless your laptop's firmware lets you change that.
Can I use a KVM with a MacBook that only has USB-C?
GL.iNet's FAQ says Comet Q can control a device whose USB-C port supports DisplayPort Alt Mode, with no HDMI port required, and lists certain MacBooks and Mac minis. Comet Pro takes HDMI in. PiKVM's FAQ has an entry noting that Apple Thunderbolt/USB-C to HDMI video may not work, and links a GitHub issue for a possible fix.
Can a KVM open the startup options on an Apple silicon Mac?
Not with keys. Apple says Apple silicon Macs have no startup key combinations; you press and hold the power button until the startup options screen appears. A KVM's keyboard emulation cannot do that, and PiKVM notes Macs lack ATX headers.
How do I stop a remote laptop going to sleep?
GL.iNet's KVMs have Mouse Jiggle, which its FAQ describes as preventing the controlled device from sleeping due to prolonged inactivity. Wake-on-LAN can wake a device from a low-power state over the network if the device supports it.
Sources & verification
Product details and prices can change. Check the linked provider before buying.
- GL.iNet KVM Docs: Quick FAQs about GL.iNet KVM Accessed 30 Oct 2026
- GL.iNet KVM Docs: Remote screen does not show the BIOS interface Accessed 30 Oct 2026
- GL.iNet KVM Docs: Comet Pro (GL-RM10) console guide Accessed 30 Oct 2026
- GL.iNet KVM Docs: Comet Pro (GL-RM10) quick setup guide Accessed 30 Oct 2026
- PiKVM Handbook: FAQ Accessed 30 Oct 2026
- PiKVM Handbook: ATX board Accessed 30 Oct 2026
- Apple Support: Mac startup key combinations Accessed 30 Oct 2026
- GL.iNet KVM Docs: GL-ATXPC ATX board Accessed 30 Oct 2026
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