StarTech ST16C552CJ ISA Serial Parallel Expansion Card 2S 1P DB9 DB25 4197-01

StarTech ST16C552CJ ISA Serial Parallel Expansion Card 2S 1P DB9 DB25 4197-01

The StarTech ST16C552CJ is an 8-bit ISA expansion card that adds two RS-232 serial ports and one Centronics-compatible parallel port to IBM PC/AT-class desktop computers using a single ISA slot. At its core is the XR ST16C552CJ dual-channel UART — an enhanced version of the TL16C550 asynchronous communications element — paired with an ILSI 18.432 MHz crystal oscillator. The two serial channels handle simultaneous serial-to-parallel and parallel-to-serial data conversion for peripherals, modems, and other RS-232 devices, while the fully bidirectional parallel port supports standard Centronics-type printers. This makes it a practical single-card solution for PC/AT systems that need all three classic system I/O ports.

Specifications & What's Included

• Model: ST16C552CJ
• Part Number: 4197-01
• Bus Interface: ISA (8-bit)
• Main Chipset: XR ST16C552CJ dual-channel UART (TL16C552-compatible), date code DC 9934
• Crystal Oscillator: ILSI 18.432 MHz
• Serial Ports: 2 × RS-232 via DB9 male connector on bracket
• Parallel Port: 1 × Centronics-compatible via DB25 female connector on bracket
• Total I/O on bracket: DB9 (serial) + DB25 (parallel)
• Form Factor: Half-length ISA expansion card with full-height bracket
• Compatible With: IBM PC/AT and compatible desktop computers with available 8-bit ISA slot
• Included: Card only — no driver disk, software, or documentation

Applications

ISA serial/parallel expansion cards like the ST16C552CJ were standard add-ins for IBM PC/AT-compatible systems throughout the late 1980s and 1990s, the era when ISA was the dominant expansion bus for desktop PCs. They were particularly common in point-of-sale (POS) terminals, industrial control workstations, and older office machines that required additional COM ports for barcode scanners, receipt printers, cash drawers, modems, or external devices, plus a parallel port for a line printer. The TL16C552 UART chipset was widely used in this class of card because it handled two independent asynchronous serial channels in a single IC, reducing board complexity. Today these cards remain useful for legacy industrial equipment, older CNC machines, lab instruments, and any application still relying on RS-232 serial communication in a PC/AT or early Pentium-era system with an open ISA slot. Replacement cards for working POS and industrial systems are a common reason buyers seek them out.