8038x > IntelA80387DX-25
Modified: April 18, 2005, 5:11 pm
Manufacturer:Intel
Model:A80387DX-25
Speed:25Mhz
Type:80387
Data Code:9018
Introduced:1987
Transistors:??
Package:68CPGA
Process:1 Micron
Architecture:80 bit FPU
Used in:80386 Systems
Description:Intel 80387 is a co-processor for 80386
microprocessor family. The 80387 runs at the same
speed as the 80386 and supports all execution
modes of the main processor - real, protected and
virtual. Being fully object-code compatible with
80287 and 8087 co-processors, the 80387 has much
greater performance due to a few factors:

Higher co-processor clock frequency.

Execution of optimized FPU instructions requires
fewer clock cycles.

Data bus is 32-bit.

The 80387 comes in two versions - 80387DX works
with 80386DX processors, and 80387SX works with
80386SX CPUs (Since the SX and DX have different
bus sizes)