IBM 85H3656 Turbo 16/4 Token-Ring PCMCIA PC Card Laptop Network Adapter

IBM 85H3656 Turbo 16/4 Token-Ring PCMCIA PC Card Laptop Network Adapter

The IBM 85H3656 is a Turbo 16/4 Token-Ring PC Card (PCMCIA) network adapter designed to connect laptop and notebook computers to Token-Ring networks. Operating at either 4 Mbps or 16 Mbps per the IEEE 802.5 standard, it fits into any standard PCMCIA Type II slot and provides Token-Ring LAN connectivity without requiring an internal expansion card. The "Turbo" designation refers to IBM's enhanced Token-Ring implementation with improved throughput and lower CPU overhead compared to earlier IBM Token-Ring PCMCIA adapters.

Specifications & What's Included

• Manufacturer: IBM
• Part Number / MPN: 85H3656
• Type: Turbo 16/4 Token-Ring PCMCIA (PC Card) Network Adapter
• Form Factor: PCMCIA Type II PC Card
• Network Standard: IEEE 802.5 Token-Ring
• Data Rates: 4 Mbps or 16 Mbps (auto-selectable)
• Bus Interface: PCMCIA / PC Card slot
• Compatible Systems: Laptops and notebooks with a PCMCIA Type II slot
• Note: The dongle/cable attachment originally bundled with this card is not confirmed to be included — please contact us to confirm what is in stock before purchasing

Applications

Token-Ring was IBM's proprietary LAN technology introduced in the mid-1980s, competing with Ethernet throughout the late 1980s and into the 1990s. Unlike Ethernet's contention-based access, Token-Ring used a deterministic token-passing protocol on a logical ring topology, which gave it predictable latency — a feature valued in manufacturing floors, financial institutions, and IBM mainframe/AS400 environments of the era. The Turbo 16/4 PCMCIA card was aimed at field service personnel, mobile sales staff, and IT professionals who needed to connect a laptop into an existing corporate Token-Ring infrastructure without carrying a docking station. Token-Ring networks were common in organizations already running IBM midrange and mainframe systems (AS/400, System/36, System/38) through the 1990s. While Token-Ring was largely displaced by Fast Ethernet by the late 1990s, legacy Token-Ring networks persisted in some enterprise environments well into the 2000s, and cards like the 85H3656 remain sought by administrators maintaining or decommissioning that older infrastructure, as well as collectors of IBM networking history.