IBM 34G1184 MCA Store Loop Adapter Card MicroChannel PS/2 C41358

IBM 34G1184 MCA Store Loop Adapter Card MicroChannel PS/2 C41358

The IBM 34G1184 is a Store Loop Adapter Card designed for IBM PS/2 systems using the Micro Channel Architecture (MCA) bus. This card provides loop adapter functionality within MCA-based IBM PS/2 workstations and servers, supporting storage subsystem connectivity in those proprietary MicroChannel environments. The PCB carries board identifier C41358 and a date code of 93 221, placing manufacture in 1993.

Specifications & What's Included

• Manufacturer: IBM
• Part Number: 34G1184
• PCB Assembly Number: C41358
• Date Code: 93 221 (1993)
• Bus Interface: MCA (Micro Channel Architecture) — full-length card
• Rear bracket: single RJ-style port
• FCC Classification: Class A (label visible on rear bracket)
• Main ICs: Texas Instruments logic/interface ICs (markings visible: 15G57673, S605 9/22, 3438.3F S4160S-388, 23921A4-4050, 3271A14 S4160S-3881)
• Blue MCA retaining brackets present on both ends
• Card only — no cables or accessories included

Applications

Micro Channel Architecture was IBM's proprietary 32-bit bus standard introduced in 1987 with the PS/2 line, replacing the older ISA bus in IBM's higher-end workstations and servers. MCA offered bus mastering, auto-configuration, and higher throughput compared to ISA, but its proprietary licensing meant it never gained wide third-party adoption. Store Loop Adapter cards like this one were used in PS/2 MicroChannel systems to connect and manage storage subsystems through IBM's internal loop topology — commonly found in mid-range PS/2 server and workstation configurations of the late 1980s and early 1990s. MCA systems were largely supplanted by PCI-based architectures by the mid-1990s, making MCA expansion cards like this primarily relevant today for maintaining, repairing, or restoring IBM PS/2 MicroChannel systems still in service or in private collections.