Intel AA635056-004 Socket 5 Motherboard 3 PCI 4 ISA Slots AT Form Factor

Intel AA635056-004 Socket 5 Motherboard 3 PCI 4 ISA Slots AT Form Factor

The Intel AA635056-004 is a Socket 5 AT-form-factor system board designed for first-generation Intel Pentium processors. It features three PCI expansion slots and four ISA slots, providing a full complement of legacy expansion options for period-correct builds, system restorations, and vintage computing setups. The board carries an Intel part number silkscreened directly on the PCB and is confirmed by the visible Socket 5 ZIF socket.

Specifications & What's Included

• Manufacturer Part Number: AA635056-004
• CPU Socket: Socket 5 (ZIF) — compatible with Intel Pentium P54C series processors
• Form Factor: AT
• PCI Expansion Slots: 3
• ISA Expansion Slots: 4
• Memory: 4 x 72-pin SIMM slots
• Onboard chipset: Intel (markings partially visible; full sub-part number not clearly legible in photos)
• Logic ICs visible on board: DM74ALS 245AWM (P48AP package, multiple)
• Rear I/O: PS/2-style DIN keyboard connector visible
• Board only — no CPU, RAM, or accessories included

Applications

Socket 5 motherboards like the AA635056-004 were Intel's platform for the original Pentium processor family, introduced in 1993 and in wide use through the mid-1990s. Socket 5 supported Pentium CPUs running at 75 MHz through 133 MHz (P54C core), and this board's combination of PCI and ISA slots reflects the transitional era when PCI was replacing ISA as the dominant expansion bus — ISA was still needed for sound cards, modems, and legacy peripherals, while PCI served faster video and disk controllers. AT-form-factor boards of this generation powered the desktop PCs of the mid-1990s business and enthusiast market. Today these boards are sought by vintage computing collectors, retro-gaming builders assembling period-accurate DOS/Windows 95 machines, and industrial users maintaining older systems that required a specific Pentium-class platform. The AT power connector and full-length ISA slots are hallmarks of this mid-1990s generation.