Trying to set up a virtual COM port emulator for a legacy device but having trouble getting it to work on my Windows PC. The device software isn’t detecting the emulated port. I need advice on compatible software and troubleshooting steps to make the connection work properly.
If You’re Dealing with Multiple Virtual COM Ports… Here’s What Worked
So, let me share a piece of my setup saga that might help fellow hams or anyone wrestling with complex COM port wrangling. After banging my head against a wall fiddling with cable splits and driver configs for days, I stumbled onto this tool: virtual-serial-port.org.
Taming the COM Port Hydra
Picture this: You’ve got an IC-7300, but also its siblings lurking on your desk—the IC-9700 and the IC-705. Now, let’s say your digital modes or logging software wants their own “exclusive” COMs for fancy stuff like CAT control or sound routing. The hardware, of course, doesn’t care about your struggles. It just sits there blinking, silently judging your life choices.
Here’s How I Cut Through the Mess
Real talk: I made virtual COM port pairs using the software from the link above. It felt like spinning up phantom cables between my radios and programs, and suddenly, that “only one program can use this port at a time” error went poof. SDR output? Routed cleanly to my FT8 decoder and logging suite—simultaneously. It synchronized CAT commands, piped audio right, and now I don’t touch the configs much at all. I literally have not seen a missed packet or crashed connection since. My configuration time dropped from “sigh… let me get coffee” to “click, done.”
TL;DR
If your shack is a jungle of serial conflicts, virtual-serial-port.org is the virtual machete. You’ll probably wonder how you survived without it.
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If your legacy device software isn’t picking up the emulated COM port, you’re not alone—Windows has a gift for making this way harder than it should be. While @mikeappsreviewer had joy with the tool from streamlining complex serial setups, I’ll add a few more tricks and different options since that method doesn’t always click for everyone.
Before diving in: MAKE SURE the software you’re emulating the port for isn’t hard-locked to super-old Windows APIs. Some legacy apps did low-level serial access that many modern emulators can’t mimic perfectly (I learned the hard way after a twelve-hour session with an ancient CNC controller).
Here’s my checklist:
- Try Alternative Software: Virtual Serial Port Driver by Eltima is arguably the most robust for compatibility. Unlike some freebie tools, it lets you create, split, join, and manage COM port pairs that your legacy software can spot.
- Check Device Manager: After you create your virtual COM pairs, look under Ports (COM & LPT). If they’re missing, your emulator isn’t running as admin, or some driver signed driver weirdness is blocking things.
- Port Numbers Matter: Many old programs only scan COM1–COM4. Assign your paired virtual ports to those numbers if possible.
- Run Everything As Admin: Always launch both the virtual port tool and your legacy app as administrator, or Windows will sometimes “ghost” the COMs—making them invisible to non-elevated apps.
- 32-bit vs 64-bit Issues: If the legacy app is 32-bit, sometimes emulators running as 64-bit processes won’t “talk” properly. Run in compatibility mode if all else fails.
And in case you’re doubting if it’s your port emulator or your app: a handy way to check if the port even gets opened is with a serial port sniffer (there’s a few free tools out there). If nothing is coming through at all, it’s a driver or permissions issue. But if the emulator lights up but the software acts dumb, the app might be to blame.
Calling a virtual serial port emulator a ‘COM port emulator for legacy devices’ makes it more search-friendly for anyone hunting a solution to run old equipment on modern PCs. These tools basically allow your computer to simulate additional serial ports in software, letting programs communicate as if real hardware ports actually exist.
So, while @mikeappsreviewer is right about that particular software being handy for ham shacks and multi-device chains, for pure legacy compatibility, I’m sticking with the tried-and-true Virtual Serial Port Driver—especially if you want less stress and more “it just works.” If you get persistent fails, ping back with what you’ve tried, Windows version, and which port numbers you’re using—sometimes it’s just a dumb checkbox you’re missing.
Honestly, virtual COM port headaches are a bit of a rite of passage. Love the deep-dive from @mikeappsreviewer and @hoshikuzu—some real solid points there—but gotta disagree on always blaming the tools. Sometimes, it’s Windows itself that’s the real party crasher. I’ve tried Virtual Serial Port Driver (yeah, the Eltima one), and while it’s not the only game in town, I find it crushes a bunch of weirder edge-cases where freeware stuff chokes.
Here’s a twist: some legacy device software hardcodes IOCTLs and low-level port calls that only play nice with genuine serial hardware. Most emulators are good, but check if your old program’s looking for hardware signals like DSR/DTR/CTS… Some COM port tools let you manually toggle these, others don’t. That’s a down-the-rabbit-hole moment that drove me nuts once until I poked at those settings.
Also, watch out for jammed up registry port assignments. Had a case where COM3–COM5 were “in use” but invisible—needed Device Manager in “Show hidden devices” mode just to nuke zombie ports. Only then would my emulator get a slot in the low-COM-number range the software would even see. Not fun.
On fresh installs: Virtual Serial Port Driver hasn’t let me down and handles advanced tricks like splitters and joining ports (good for you if your old device likes to chat in multiple directions). Pro-tip: always check both Device Manager and the app’s log window, if it has one, to see handshake errors.
Anyway, if you’re struggling to even start, I suggest getting the latest build and steps from their Virtual Serial Port Driver setup guide to make sure you’re not missing anything weird. Sometimes the basic install can trip up if you have bone-dry system libraries or unsigned drivers.
So yeah, sometimes it’s NOT YOU, it really is the janky nature of virtualizing ancient hardware protocols. If you’re still stuck, what device/software is it, and which COM ports show as taken? You might just be one device cleanup away from legacy-hack bliss.
Common trap: thinking every legacy serial app is going to magically see your virtual ports. Some oldies are coded to expect hardware-level signals—stuff like ring indicator (RI), carrier detect (CD), or strict DSR/CTS handshakes. Many open-source emulators gloss over that, so even if your shiny virtual port shows up in Device Manager, your app sits there, arms crossed, waiting for a signal it’ll never get.
My approach: dive deeper with Virtual Serial Port Driver—not free, but rock-solid if you need full RS-232 signal emulation out of the box. It mirrors hardware lines (DTR, RTS, etc.), so even neurotic legacy apps get fooled into working. Bonus: it handles splitting and joining ports if you ever need one-to-many or many-to-one setups, which doesn’t always work with some tools favored by others here.
Pros:
- Stellar hardware handshake emulation—essential for crusty software.
- Super intuitive UI; quick to pair up ports and configure advanced behaviors.
- Handles chained and split virtual ports smoothly for complex configs.
Cons:
- Not free (trial exists, but long-term use means paying).
- Can conflict with certain security software on first install—allow it in your AV/firewall settings!
Competitors mentioned by others make sense for simple use cases or a quick fix, but they sometimes choke on the super-niche demands of old serial control suites. And, crucially, always scrub ghosted devices (Show hidden in Device Manager), or Windows will silently reserve COM numbers and trip you up—a tip echoed above, and I can’t stress it enough.
Summary: If the “port shows but isn’t detected” issue persists, it’s probably handshake signals or COM number bloat in Windows, not the emulator itself. Use Virtual Serial Port Driver if you need real hardware-level compatibility, but do some “spring cleaning” in your device list first. Sometimes, legacy bliss is just a registry purge away.