8038x > IntelRAPIDCAD-2

Modified: April 18, 2005, 5:25 pm

Manufacturer:	Intel
Model:	RAPIDCAD-2
Speed:	33MHz Max
Type:	80387
Data Code:	9215
Introduced:	1991
Transistors:	??
Package:	68CPGA
Process:	0.8 Micron
Architecture:	Programmable Logic Device
Used in:	80386 Systems
Description:	The RapidCAD is not a coprocessor, strictly seen, although it was marketed as one. Rather, it is a full replacement for a 80386 CPU: basically, an Intel 486DX CPU chip without the internal cache and with a standard 386 pinout. RapidCAD is delivered as a set of two chips. RapidCAD-1 (S- Spec: SZ624) goes into the 386 socket and contains the CPU and FPU. RapidCAD-2 (S-Spec: SZ625) goes into the coprocessor (387) socket and contains a simple PAL(Programmable Array of Logic) whose only purpose is to generate the FERR signal normally generated by a coprocessor (This is needed by the motherboard circuitry to provide 287 compatible coprocessor exception handling in 386/387 systems.) The RapidCAD instruction set is compatible with the 386, so it doesn't have any newer, 486-specific instructions like BSWAP. However, since the RapidCAD CPU core is very similar to 80486 CPU core, most of the register- to-register instructions execute in the same number of clock cycles as on the 486. http://www.cpushack.net/RAPIDCAD.html