MS-4144 © 1994 MSI [Micro-Star International, Co. Ltd.]
The MS-4144 (highly documented through its prominent Ver 2.1 retail layout) is a legendary, high-performance late-generation Socket 3 PCI/ISA Baby AT motherboard engineered and manufactured by Micro-Star International (MSI) between late 1994 and 1996. Designed as a flagship hardware canvas for the late 486 computing era, the board centers around the ultra-stable, highly optimized Silicon Integrated Systems (SiS) 496 (Green PC PCI Host Controller) and SiS 497 (PCI Mega I/O Southbridge) core logic chipset cluster. The mainboard hosts a flexible 237-pin Socket 3 footprint paired with a sophisticated onboard hardware switching Voltage Regulator Module (VRM). This layout supplies native, drop-in multi-voltage support (5V down to 3.3V/3.45V) for an exhaustive range of microprocessors, including Intel i486DX/DX2/DX4, AMD Am486, Enhanced Write-Back lines, and late-generation AMD Am5x86-P75 or Cyrix 5x86 upgrade chips running on synchronous Front-Side Bus (FSB) speeds from 25 MHz up to 40 MHz (and unofficially 50 MHz). Peripheral scaling bridges platforms cleanly, offering three high-speed 32-bit PCI slots alongside four legacy 16-bit ISA slots, backed by four 72-pin SIMM sockets supporting up to 128 MB of Fast Page Mode (FPM) or Write-Back EDO DRAM and an expandable socketed L2 secondary static cache (SRAM) DIP matrix supporting up to 1 MB.
The Ultimate 486 Overclocking Sandbox: The MS-4144 Ver 2.1 is highly revered by modern retro-computing benchmark enthusiasts because its PCB copper trace layout contains more hardware multiplier and FSB configuration jumpers than almost any other Socket 3 board of its generation. While officially rated for a 33 MHz or 40 MHz bus, hardware modders frequently exploit its native "CPU/2" PCI divider clock-gating lines to safely run an AMD Am5x86-133 chip at a blistering, overclocked 160 MHz (4x 40 MHz) or an ultra-rare 50 MHz FSB layout without crashing the PCI bus stability framework.
The Easy PS/2 Mouse Modification: In its standard commercial factory configuration, the MS-4144 shipped only with standard legacy serial communication ports and a DIN-5 AT keyboard socket. However, MSI cleverly left the entire trace hardware footprint and internal logic routing for a modern PS/2 auxiliary mouse port completely open on the PCB (near jumper header J5). Modern retro-hardware archeologists frequently perform a clean through-hole soldering modification—adding two 47pF capacitors, 2.2uH inductors, a 5-pin header, and bridging trace SMD pad R147 to link the keyboard controller (KBC Pin 36) to IRQ 12—unlocking native hardware PS/2 mouse capabilities under Windows 95 without using up a valuable serial port or an ISA slot.