Skip to Content
Skip to Table of Contents

← Previous Article Next Article →

ATPM 6.08
August 2000


How To



Download ATPM 6.08

Choose a format:

Review: Stealth Serial Port

by Evan Trent,




Price: $49.95

Requirements: iMac, Blue and White Power Mac G3, or Power Mac G4


The migration to USB has been an interesting experience for many Mac users. Indeed a plethora of USB devices has sprouted up, and several Mac Serial to USB converters are now available. Yet many users are faced with legacy devices, many of which do not function properly when interfaced with a Serial to USB converter.

Apple MIDI is one such example—Apple has not updated their drivers in ages, and hence they do not work with USB MIDI adapters. Many applications require Apple MIDI and do not work with other third party MIDI drivers such as Free MIDI or OMS (Open MIDI System). What should a user who depends on Apple MIDI do if he wants to use a new USB-only Macintosh? What should users in similar situations do? The new Macs are irresistible, but legacy devices always complicate the decision to purchase a new machine. Stealth Serial Port to the rescue.


The Stealth Serial Port is a $50 card that plugs into the comm slot found on the iMac, Blue and White G3, and G4 computers. It provides a standard Mini DIN-8 Serial port (note—the Stealth Serial port does not support GeoPort devices, which require a 9th pin). The only bad news is that because the Stealth card uses the comm slot in your box, you will lose the internal modem. That’s not such a bad thing in my opinion. I never liked internal modems to begin with (don’t get me started). When I had my G4 built at the Apple Store I knew that I would be purchasing a Stealth Serial Port so I purchased it without the modem. If you need a modem, there are numerous external USB models from which to choose, and in the end you won’t be spending much more, if any, for an external modem.

Installing the card is absurdly simple. If you have a B&W G3 or G4 the procedure requires about two minutes. For iMacs it’s a bit more involved but still quite manageable.

That the Stealth Serial Port uses the comm slot is of critical importance with respect to its superlative compatibility. The driver included with the Stealth card simply hooks into the Comm Toolbox, providing another port selection in the port pop-up menu of any Comm Toolbox savvy application. For older applications, simply choosing the Modem port will work. Apple has cleverly patched the Modem port to the comm slot so that older applications will work with the internal modem (this has been common practice since the days of the first internal modems in Apple’s laptops).


Does it work? Yes! It works superbly. I have used it with both Comm Toolbox-savvy and older applications; both find the Stealth port and use it without fail. The port supports the faster speed of 230.4K transmission, which is good news if you are forced to use the serial port for digital camera transfers, for example. Also supported is Ethernet to LocalTalk bridging, so you can network an old LocalTalk printer on an Ethernet network. Even that Godforsaken Apple MIDI works now! I have yet to find a program, no matter how old, which does not work perfectly with the Stealth Serial Port.

I have followed discussions regarding competing cards, and it has become evident to me that the GeeThree product is by far the best choice. Other cards are apparently not as compatible—and I have yet to hear any complaints regarding the Stealth board. When compared to Serial to USB converters the GeeThree card always comes out ahead. And often it is cheaper.

Any complaints? In terms of functionality, no. The card does what it says it will, and it does it perfectly. The manual is appropriately short but easy to follow, and it will allow even the novice to install the board. The driver is a tiny little extension with next to no memory overhead. I cannot find any problems with the card.


The only way to improve upon the product would be to somehow design a similar board with both an internal modem and serial port. Such a card would then provide an accompanying driver that would allow Comm Toolbox applications to choose between Internal Modem and Stealth Port, and there would be a control panel allowing the user to choose which port to map old style modem port requests. This would be perfection…but I cannot penalize the folks at GeeThree for not providing a product I just thought up off the top of my head.

I can summarize this review quickly for you: the Stealth Serial Port is about as perfect a product as I’ve encountered, at least from a hardware standpoint. Its perfection is a result of its simplicity, but it is nevertheless flawlessly executed and the price is tough to beat. Thankfully, we are leaving the days of the serial port behind us, but many Mac users will nevertheless encounter the need for one. Should that need arise, rest assured that the GeeThree will come to the rescue in fine style.

appleCopyright © 2000 Evan Trent, Reviewing in ATPM is open to anyone. If you’re interested, write to us at

Reader Comments (11)

Alvester Duckworth · November 10, 2003 - 18:53 EST #1
Where do I order this product?
Evan Trent (ATPM Staff) · November 11, 2003 - 00:48 EST #2
Barry · December 6, 2003 - 15:10 EST #3
Is the software compatible with Panther?
Lee Bennett (ATPM Staff) · December 7, 2003 - 00:45 EST #4
Barry - yes, there is a Panther-compatible installer. The best advice we can give is to visit GeeThree's web site and either click the Products link to find out if there's an updated version of the hardware card and click the Downloads link to obtain the most recent (and Panther-compatible) installer.
Mark · January 26, 2004 - 11:06 EST #5
Why is my serial port ghosted when I install the newest version of the stealth driver, version 1.2? I can not apply the driver in my network configuration.
LARRY · June 8, 2004 - 13:54 EST #6
hi, i have the option of getting a stealth serial port card with another item, but wonder if it will work on my computer. i have a mac 9600 with a G3 upgrade in it. thanks, LD
Evan Trent (ATPM Staff) · June 8, 2004 - 15:09 EST #7
No the Stealth Serial Port was only designed to work on specific machines. The original iMac series, the B&W G3, and Yikes G4.
Rudolph Gorsch · November 21, 2005 - 07:28 EST #8
Used to drive a serial printer, where would I look to find the printer? Or, would it appear in the printer list? (G4 w/OS 10.3.x)

Erik · May 16, 2006 - 15:54 EST #9
Anyone know where this G3 version can be purchased? It's May 2006, and as this is an older device, I've scoured the Internet to no avail. If you know, please email me at: (substitute ejl for xxx)

Brian Catt · November 21, 2007 - 08:58 EST #10
Getting one on ebay, this was really useful support. It was advertised as a MODEM card, which I don't think it is, but what I want to do is support my external Global Village MODEM from my old style G3 Mini Tower - so this looks just perfect I may need to find an OSX driver for it if I want to run it native versus in Classic Mode though?????????????
Brian Catt
01932 772731
Skype CattHouse
John M. Davis · February 19, 2008 - 16:55 EST #11
Will the stealth serial port work with black and white Powerbook G3 series M4753 to connect with HP officejet 4315 All in One Printer? What does the ADB printer port look like?

Please help, I need to connect printer to laptop. Johnny

Add A Comment

 E-mail me new comments on this article