Cables Unlimited 2 -Port DB9 Serial PCI I/O Card (IOC2200) Standard Card

Great card, (What's this?) Very easy install for this card.
Mixed feelings, I will have to admit, I have mixed feelings about this product. I have purchased them before and had absolutely no problems. In fact, I am using one right now on my workplace PC and it has performed flawlessly since installation. However, I had occasion to purchase two more - one to replace a port damaged by lightning and one to keep as a 'back up' in case of more failures (at work). I installed the new port card and the computer would not boot, giving me an error message about 'operating system not found'. I ended up taking the computer to the repair shop and the problem was identified as the new port card.
Manufacturer out of business, (What's this?) The manufacturer is out of business, so info might be scarce.
Won't work on Windows XP, (What's this?) The drivers do not work correctly on Windows XP. The web site listed in the manual to download updated drivers is no longer working, the site has disappeared.
Standard Card, (What's this?) When I tried to install the card, I found that it will not work in the new computer that I bought. It is a PCI bus rather than the PCIE bus. A day or two of research led me to the correct card which I ordered from another source.

All was not lost as I decided to upgrade the memory in my old computer and retain it in case the Windows 7 computer proves unsatisfactory. The PCI card fits there, so I now have 3 serial ports plus some USB ports in my XP Pro computer.
Think Twice, Product seemed good - installed easy and went through setup. But doesn't have drviers to make it work for Windows XP. I tried to contact manufacturer which isn't possible. I even searched web for over an hour for a driver that would make it work - couldn't find one. So for the one I bought, and the driver CD that came with it, it is completely useless. Plan on returning if I still can and have already ordered another one from a different manufacturer that works fine.
Questionable but works, (What's this?)

Pin header serial port connector x 1

Compatible with standard 16C550 UART with 16 byte transmit-receive FIFO

PCI Specification Revision 2.1 compliant

DB9 serial port connector x 2

Fast data rates up to 1 Mbytes/sec

Pin header serial port connector x 1.Compatible with standard 16C550 UART with 16 byte transmit-receive FIFO.PCI Specification Revision 2.1 compliant.DB9 serial port connector x 2.Fast data rates up to 1 Mbytes/sec. This easy to install and configure PCI card from Cables Unlimited adds 2 extra high-speed serial port to any PC. This simple and reliable card is compatible with any serial peripheral and provides the most convenient way of connecting PCs to external modems, serial printers, Palms, mice, point-of-sale devices, digital cameras, etc.

Best Connectivity SD-PCI15024 PCI One Serial Port Card with SystemBase Chipset SB16C1052PCI I bought 2 that never worked with Linux

I bought 2 that never worked with Linux, (What's this?) I bought 2 of them for external serial modems and neither of them ever worked in Ubuntu 11.10 systems. The vendor never replied to my attempts to contact them. Thankfully Amazon took them back and gave my money back.
Perfect for 1, (What's this?) If you only want to use one console cable, this one is perfect. I use it to connect to cisco switches routers and asa appliances. If you only need one connection, go with this. Otherwise, I would say to go with the dual console.
It Works on a Dell 4400 with XP Pro SP3, (What's this?) It works fine with no issues on Dell 440 WinXP Pro SP3. Using it to print to Automated Packaging Systems Precision Printers. I previously tried the Startech brand and they did not work.

PCI one serial ports card with SystemBase Chipset SB16C1052PCI. Easy Plug & installation automatically selects IRQ and I/O address. Fully compliant with PCI Local Bus Specification Revision 2.3. Supports PCI power management. Supports PCI IRQ sharing feature, saves valuable resources for other add-on cards. Compatible with industrial standard 16C550 UART. On-chip 256-byte depth FIFO in Transmit & Receive paths of each port. Fast data rate up to 115.2Kbps on each port. Supports hardware and software flow control. Supports 5-, 6-, 7-, 8-bit serial format. Supports Even, Odd, None, Space & Mark parity. Supports 1, 1.5, or 2 Stop bit operation. Hardware: Computer with PCI slot.

StarTech.com 1 Port Low Profile Native PCI Express Serial Card with 16950 (PEX1S952LP)

Native single-Chip, single lane PCI Express

High Performance Single Channel Oxford 950 UART

Less load on the CPU (Up to 48% Less)

128-byte deep FIFO per transmitter and receiver

Equipped with a low profile bracket for PnP support for Micro and Slimline PC form factors.

Native single-Chip, single lane PCI Express.High Performance Single Channel Oxford 950 UART.Less load on the CPU (Up to 48% Less).128-byte deep FIFO per transmitter and receiver.Equipped with a low profile bracket for PnP support for Micro and Slimline PC form factors.. This low profile/half-height PCI Express Serial card adds an RS232 (DB9) Serial Port to a computer through an available PCI Express slot, while relying on a native, single-chip design (Oxford OXPCIe952) that harnesses the capability of true PCI Express - ensuring maximum performance and reliability and reducing the load applied to the CPU by as much as 48% over conventional (bridge chip) serial cards. The PCIe Serial Card features a low profile/half-height mounting bracket that's designed specifically for low profile/small form factor computer cases; compatible with a broad range of operating systems, including Windows 2000/XP/2003/Vista, and Linux Kernel 2.6.11 and up, the PEX1S952LP PCI Express Serial Card is backed by StarTech.com''s Lifetime Warranty and free lifetime technical support.

NEW RS-232 Serial Converter (Networking)

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VScom 200E PCIex

Extra bracket for Low Profile cases

PCI Express x 1, 2 x RS232

PCI Plug and Play, Drivers for Windows 2000, XP, 2003 and Vista

16C950 (128 Byte FIFO), 921 kbps

Extra bracket for Low Profile cases.PCI Express x 1, 2 x RS232.PCI Plug and Play, Drivers for Windows 2000, XP, 2003 and Vista.16C950 (128 Byte FIFO), 921 kbps. The VScom 200E PCIex is an add-on card for PCI Express, providing two serial ports. These high speed serial ports with their 128 byte long FIFO are best for high speed communication, even in heavy loaded systems.Many unique features reduce the system load. They also allow very unusual speed settings such as 500.000bps. The extra bracket allows to place the card in Low Profile cases.

Best Connectivity SD-PEX15021 PCI-Express RS232 1x Serial Port PCI express serial card

Have not figured out how to use the "re-map function for legacy ports", (What's this?) Works well on Windows 7, but have not figured out how to use the "re-map function for legacy ports". Drivers are available on mini-CD and online, but I have not been able to find any other technical documentation.
PCI express serial card, (What's this?) These cards worked great! I am using them in Dell Vostro 260 PCs with Windows 7 x64.
The driver is on the small CD included and then Windows had an update for it also.
New PCs do not have regular PCI slots only PCI express.
PC will not boot once this card is inside, (What's this?) I bought this card for its price, simplicity, "future-proof" PCI-e interface and the two reviews here. Problem is, once it's installed the PC (Dell Dimension 3100) will not boot - HD spins up but nothing else happens (at least for an hour or so). Powering down and pulling this card out lets the system boot properly. Updated BIOS to current rev with no change. There are no BIOS settings for enabling/disabling/modifying the PCI-e 1x slot.
Though the directions say to put the card in and install the drivers when Windows looks for them, on a chance I installed the cards downloaded from the specified site - again with no change in the non-booting behaviour.

No idea why it is preventing booting, but it's going back to Amazon and I'll be getting a plain old PCI rs232 card instead.
Works Well! Great Speed!, (What's this?) I bought this card for a new slim-sized computer which didn't have a serial port on the motherboard. I am using this card for a old Sabre ticket printer. I installed the latest drivers(WHQL) from the card's manufacture's website. It is more reliable than USB-to-serial adapters. Installation was very easy. PCI express cards are the ones to buy because all new computers will not have PCI slots.
Reviewing the Best Connectivity SD-PEX15021 PCI Express RS232 1x Serial Port, (What's this?) I received this product and wasn't quite sure what to make of the tiny plug-in edge card. Only when I realized that it could plug into any PCI express port, given the "notch" in the board lined up correctly, did I decide to give it a try.

Bingo! This card works wonderfully and is used as a CAT (Computer Aided Tranceiver) control port for my Amateur Radio Tranceiver. There is no problem, my computer immediately recognized the RS232 PCI express card.

This is a fine product for the cost and offers the additional RS232 serial port I required to match my radio with computer software.

Best Connectivity 1-Port RS-232 Serial PCI Express x1 Controller Card General Features:

Single-lane PCI Express x1 interface w/2.5 Gbps throughput

Supports re-map function for legacy ports

Fully compliant with PCI Express Base Specifications Revision 1.0a

MOSCHIP MCS9901CV One (1) 9-pin RS-232 Serial port

Best Connectivity 1-Port RS-232 Serial PCI Express x1 Controller Card General Features:.Single-lane PCI Express x1 interface w/2.5 Gbps throughput.Supports re-map function for legacy ports.Fully compliant with PCI Express Base Specifications Revision 1.0a.MOSCHIP MCS9901CV One (1) 9-pin RS-232 Serial port. PCI-Express RS232 1x Serial Port with MSC9901 Chipset. Fully compliant with PCI-Express Base Specification Revision 1.0a. Single-Lane (x1) PCI-Express with throughput up to 2.5Gbps. Low profile ready with extra low profile bracket. Compatible with industrial standard 16C550 UART. On chip 256-byte depth FIFO in transmit. Transfer data rates up to 250Kbps on each port. Supports hardware and software flow control. Supports 5, 6, 7, 8-bit serial format. Hardware: Computer with PCI-Express card slot.

Startech Com 2 Port Pcie Rs232 Serial Adapter Card

Data Link Protocol RS-232

Networking Interface PCI Express x1

Networking Type Serial adapter

Form Factor Plug-in card

Connectivity Technology Wired

Data Link Protocol RS-232.Networking Interface PCI Express x1.Networking Type Serial adapter.Form Factor Plug-in card.Connectivity Technology Wired. This PCI Express Serial Adapter card can be installed into any PCI Express slot on a computer, to provide two high performance 16C950 RS232 serial UART channels/ports - a convenient solution for connecting modern or legacy serial devices with support for data transfer rates of up to 460 Kbps. The serial adapter card is easy to install, with support for Windows® 2000, XP, 2003 and Vista. Plus, the card features IRQ sharing and supports plug and play serial device connections, guaranteeing convenient, hassle-free installation. The 2 Port PCI Express 16C950 Serial Card is backed by StarTech.com?s lifetime warranty and FREE LIFETIME tech support.