Zenith Data Systems 85-3053-02 Parallel Serial Board 8-Bit ISA Card 112785

Zenith Data Systems 85-3053-02 Parallel Serial Board 8-Bit ISA Card 112785

The Zenith Data Systems 85-3053-02 is an 8-bit ISA parallel/serial I/O expansion card designed for Zenith Data Systems ISA-bus personal computers. It adds parallel and serial port connectivity to compatible ZDS desktop systems via a DB-25 bracket connector, and is populated with standard 74-series TTL logic ICs typical of mid-1980s ISA I/O card design.

Specifications & What's Included

• Manufacturer: Zenith Data Systems
• Part Number: 85-3053-02
• Board Stamp: 112785 (November 1985)
• Bus Interface: 8-bit ISA
• Function: Parallel and Serial I/O expansion
• Bracket Connector: DB-25 female (parallel port)
• Form Factor: Half-length ISA expansion card
• Main Logic ICs: SN74ALS32N, 74LS74AN (TTL series)
• Country of Manufacture: Malaysia (per board label)
• Included: Card only — no cables or accessories

Applications

8-bit ISA parallel/serial I/O cards like the 85-3053-02 were standard expansion hardware in IBM PC/XT-compatible and proprietary ISA-bus desktop computers of the mid-1980s. Zenith Data Systems was a major supplier of IBM-compatible PCs to the U.S. government and commercial markets during this era, and produced a range of proprietary peripheral cards for their ZDS desktop lines. This card would have provided parallel printer port connectivity and serial communications capability — functions that in later designs were integrated onto the motherboard. Today these cards are sought by collectors and technicians maintaining vintage ZDS systems, or by hobbyists restoring period-correct ISA-bus machines. The 8-bit ISA bus standard dates this card firmly to the pre-AT/286 era of the mid-1980s.