Wyse 990205-01 8-Bit ISA Dual Serial Parallel I/O Card NS16450 UART DB25 DB9

Wyse 990205-01 8-Bit ISA Dual Serial Parallel I/O Card NS16450 UART DB25 DB9

The Wyse 990205-01 is an 8-bit ISA expansion card providing two serial ports and one parallel port for IBM PC/XT and ISA-compatible systems. It carries two NS16450 UART chips to handle the dual RS-232 serial channels, with a DB9 serial connector and a DB25 parallel connector mounted on the rear bracket. Manufactured by Wyse Technology and made in Taiwan, this board is identifiable by the "DUAL SERIAL/PARALLEL ASSY.990205-01" silk screen printed on the PCB.

Specifications & What's Included

• Manufacturer: Wyse Technology
• Part Number / Assembly: 990205-01
• Bus Interface: 8-bit ISA
• Serial Ports: 2 × RS-232 (DB9 bracket connector)
• Parallel Port: 1 × DB25 bracket connector
• Serial Controller Chips: 2 × National Semiconductor NS16450 UART
• Additional ICs: MC1489A line receiver, SN75150P (×2) RS-232 driver
• Form Factor: Half-length ISA expansion card
• Country of Manufacture: Taiwan (per rear label)
• FCC Class B certified (per rear compliance label)
• Board only — no software or documentation included

Applications

8-bit ISA serial/parallel combo cards like the Wyse 990205-01 were standard expansion hardware for IBM PC/XT-class machines and early AT-compatible systems from the mid-1980s onward. They were used to add or replace COM port and LPT port capability, connecting peripherals such as serial mice, modems, terminals, dot-matrix and daisy-wheel printers, and external storage devices. Wyse Technology was widely known at the time for its terminals and PC peripherals, and cards of this type were common in business and industrial PC installations of the era. Today these cards are sought by collectors and by maintainers of legacy systems — industrial controllers, CNC machines, and vintage computers — that still depend on 8-bit ISA slots for serial and parallel I/O expansion.