We take cryptocurrency — so the coins you hold can buy real hardware.Pay in crypto, spend it on real hardware. Free insured shipping worldwide over $399. Plain, unbranded boxes, sent from Germany.Free insured shipping over $399. Your rate is locked for 30 minutes once checkout opens.Rate locked 30 minutes. Every item sealed, serial-checked and covered by a 24-month warranty.Sealed, 24-month warranty.

Saved items Sign in
Green PCIe expansion card with two DB9 serial ports and low-profile bracket

STARTECH

STARTECH 21050PCSERIALCARD 2-Port PCIe RS-232 DB9 Serial Laptop Add-on Card

SKU CH-PSBH-T03S1 MPN 21050PCSERIALCARD

Adds two RS-232 DB9 serial ports via PCIe for legacy device connectivity

  • TypeAccessories
  • Adds two RS-232 DB9 ports via PCIe for legacy device connectivity
  • 16C1050 UART with 256-byte FIFO enables reliable serial communication
  • Up to 921.6 Kbps per port supports high-speed data transfer
  • Low-profile brackets included for Small Form Factor system installation
  • Compatible with Windows and Linux operating systems for broad deployment

Two-Port RS-232 PCIe Card

This StarTech card adds two DB9 serial ports to a desktop or small-form-factor system through a single PCIe slot. It targets engineers, integrators and technicians who still operate industrial equipment, point-of-sale terminals, security panels or A/V gear that requires native RS-232 connectivity.

921.6 Kbps Sustained Throughput

Each port uses a 16C1050 UART with 256-byte FIFO buffers to maintain bi-directional data rates up to 921.6 Kbps without host CPU bottlenecks. The deep FIFO and hardware flow control keep long transfers stable, so logging sessions or machine-control streams do not drop characters under continuous load.

Low-Profile Brackets and Port LEDs

A low-profile bracket is included for tight chassis, while standard-height brackets fit full-size cases. LED indicators on each DB9 connector show link and activity status at a glance, simplifying cable verification and fault diagnosis in rack or cabinet installations.

Highlights

  • Adds two RS-232 DB9 ports via PCIe for legacy device connectivity
  • 16C1050 UART with 256-byte FIFO enables reliable serial communication
  • Up to 921.6 Kbps per port supports high-speed data transfer
  • Low-profile brackets included for Small Form Factor system installation
  • Compatible with Windows and Linux operating systems for broad deployment

Specifications

TypeAccessories
Shipping weight0.49 kg
Package size203 × 152 × 51 mm

Questions about this item

How much heat or power does the 21050PCSERIALCARD draw when running both ports continuously?

The card uses a 16C1050 UART with 256-byte FIFO buffers, which keeps power draw low enough for passive cooling inside a desktop or SFF chassis.

What bracket or slot must my system already have for this card to install?

A free PCIe slot is required; low-profile brackets are included for Small Form Factor systems.

Will the 921.6 Kbps ports work reliably with my older RS-232 equipment?

Yes, the dual DB9 ports support bi-directional speeds up to 921.6 Kbps and are designed for legacy serial devices in logistics, manufacturing and POS environments.

New to this? Which coin should you pay with — what to check, what it costs to pay, and what is never asked for.

Also in this aisle

People compared these

Same shelf, same checkout — eight coins and a 30-minute rate lock.