ATC-1415 © 1994 A-Trend.
The ATC-1415 is a high-performance 486 motherboard built for the absolute peak of the VLB era. Before A-Trend fully committed to PCI with the 1425 line, the 1415 was the "go-to" board for users who wanted to push the 486DX2 and DX4 processors to their limits using the established, high-bandwidth VLB standard.
Chipset: UMC UM8498F / UM8496F (a very high-performance chipset that was often faster than the later SiS 496/497 boards).
CPU Support: Socket 3 (supports 486SX/DX/DX2/DX4).
Expansion: 2x VLB slots, 5x ISA slots.
Memory: 4x 72-pin SIMM sockets (typically supporting up to 128MB, which was enormous for 1993/94).
Cache: 256 KB of L2 cache (usually in 8x DIP sockets + 1 TAG chip).
Form Factor: Baby AT.
The UMC Advantage: Many collectors actually prefer the atc1415 over the later atc1425a/b because the UMC chipset used here provided significantly lower latency for memory and VLB access than the SiS 496/497 chipset used in the 1425 series. If you wanted the absolute fastest 486 "DOS gaming" machine in 1994, this was the board to have.
The VLB "Triple-Threat": The ATC-1415 was famous for its ability to handle "bus mastering" VLB cards (like high-end SCSI controllers or early video capture boards) without the system crashing—a problem that plagued cheaper VLB boards.
The Jumper Map: The silk-screening on the ATC-1415 is surprisingly excellent. Unlike the 1425A where you were left guessing, the 1415 had almost all CPU voltage and clock multiplier settings clearly printed directly on the PCB.