HP 5064-3691 5183-2783 ISA Expansion Backplane Board PC Workstation 4-Slot Rev A

HP 5064-3691 5183-2783 ISA Expansion Backplane Board PC Workstation 4-Slot Rev A

The HP 5064-3691 is an ISA expansion backplane board designed for HP PC workstations. The board carries the silk-screened part number 5183-2783 Rev A, and serves as the passive card-cage backplane that routes the ISA bus to multiple expansion slots, allowing peripheral cards to be installed in a chassis-mounted configuration separate from the main system board.

Specifications & What's Included

• Manufacturer: HP (Hewlett-Packard)
• Spare / Assembly Part Number: 5064-3691
• Board Part Number (silk screen): 5183-2783
• Revision: A (Rev A--63)
• Bus Type: ISA (Industry Standard Architecture)
• Expansion Slots: 4 ISA expansion slot connectors (visible on front face of board)
• Additional edge connector present for system bus interface
• PCB: Green, multi-layer
• Rear side: solder side only — no rear-mounted components
• Included: Board only — no cables, mounting hardware, or accessories

Applications

ISA backplane boards like the HP 5064-3691 were used in HP tower and desktop workstations of the late 1980s through mid-1990s — the era when the ISA (AT) bus was the dominant expansion standard for IBM-compatible PCs. Rather than soldering expansion slots directly to the motherboard, some HP workstation designs used a passive backplane architecture: the CPU and memory resided on a processor card that plugged into the backplane, while peripheral cards (graphics, SCSI, network, serial/parallel I/O) each occupied their own ISA slot on the same backplane. This approach simplified card swaps and chassis serviceability. Today these boards are primarily sought by technicians maintaining legacy HP workstations, vintage computing enthusiasts, and system integrators keeping older HP equipment in service.