This is a DayStar Digital Turbo 040 processor accelerator card designed for Apple Macintosh computers.
It features a Motorola 68040 processor running at speeds up to 40 MHz, significantly upgrading the performance of older 68030 Macs.
The card was engineered to fit into the Processor Direct Slot (PDS) of various Mac models, including the Macintosh IIci, IIsi, and SE/30.
The XC68040RC40M is a 40 MHz Motorola 68040 full microprocessor featuring an integrated Memory Management Unit (MMU) and Floating Point Unit (FPU). It is frequently found on vintage high-performance processor upgrades like the DayStar Turbo 040 accelerator card for vintage Macintosh systems.
I have not tested this card. Cosmetically it appears as normal. Selling as shown in photos.
Wayne
"Welcome to Macintosh" movie
the Collector