MS-4132 G Ver:1 © 1992 MSI [Micro-Star International, Co. Ltd.]
The MS-4132 G (Ver:1) is an early-generation, transitional 486-class VESA Local Bus (VLB) Baby AT motherboard engineered and manufactured by Micro-Star International (MSI) around 1992 to 1993. Built to offer a scalable bridge from legacy ISA workstations to the early demands of 32-bit local-bus graphics, the mainboard is centered around the Silicon Integrated Systems (SiS) 85C461 Rabbit core logic chipset. The mainboard hosts a 237-pin Socket 3 (or occasionally Socket 2) footprint, supporting Intel 486DX, DX2, and early compatible clones running on synchronous Front-Side Bus (FSB) speeds of 25 MHz or 33 MHz. Peripheral expansion relies on a dual-standard infrastructure: two 32-bit VESA Local Bus (VLB) slots for high-speed video/disk controllers, alongside seven 16-bit ISA slots for legacy peripheral support. Memory handling is designed for early-era density, featuring four 30-pin SIMM sockets supporting up to 32 MB of Fast Page Mode (FPM) DRAM, complemented by a dedicated DIP socketed L2 secondary static cache (SRAM) matrix supporting 64 KB or 128 KB.
The Rabbit Legacy: The SiS 85C461 chipset, nicknamed Rabbit by the hardware engineering community at the time, was the cornerstone of MSI’s early VLB success. While it didn't support the high-speed "Burst" cache modes of later SiS 471 chipsets, it was incredibly stable at 33 MHz, making the MS-4132 G a preferred choice for corporate reliability in an era where VLB was still considered experimental and prone to bus-noise crashes.
The 30-Pin SIMM Bottleneck: Unlike later MS-41XX boards that transitioned to 72-pin SIMMs, the MS-4132 G is strictly tied to the 30-pin memory ecosystem. This forces users to populate memory in sets of four (to match the 32-bit bus width of the 486), creating a significant limitation for upgrading to 64 MB. For many retro-enthusiasts today, this makes the MS-4132 G a challenging but rewarding build, as high-capacity 30-pin SIMMs are now rarer and more expensive than their 72-pin counterparts.