QUESTION:
What type of computer is the Pathfinder utilizing? Is the CPU from Intel or
Motorola or custom made? How fast does it run and how much memory does it
contain? Is there more than one computer on board? What programming language
was utilized in the software?

ANSWER from Bridget Landry on April 28, 1997:
The rover code is written in C and assembly language.  This code implements
a custom command set tailored to the specific hardware/software
capabilities of the rover.

ANSWER from Lloyd Keith:
The computer is a Radiation Hardened IBM Risc 6000 Single Chip (Rad6000 SC)
CPU. It is the same as the IBM R6000 workstation. Lockeed-Martin Federal
Systems in Manassas, VA, is responsible for doing the radiation hardening of
the Rad6000 SC as well as developing the complete Mars Pathfinder Flight
Computer (MFC).

The MFC contains 128 MBytes of DRAM memory and runs at speeds of 2.5, 5, 10
and 20 MegaHertz. This translates to approximately 2.7, 5.5, 11, and 22 MIPS
(this does vary, depending on which benchmark is being used). The code was
developed using VxWorks as the real-time OS and "C" and assembly languages.
It utilizes object-oriented constructs.

On the system there is only one computer to control the spacecraft
throughout all phases of the mission. The Rover has a very small CPU that it
uses once we have landed and the rover is released. All communications to
Earth from the spacecraft and rover come through the Rad6000 SC.

--Lloyd Keith, MFC (Mars Pathfinder Flight Computer) Chief Engineer

ANSWER from Charles Whetsel on June 26, 1997:
The Mars Pathfinder Flight Software was written in the C programming
language.  The computer chip is from the RS6000 family (a space-qualified
radiation-hardened derivative), which is commonly used in UNIX workstations
and was the predecessor to the PowerPC chip used in Macintosh computers.

ANSWER from Steve Stolper on July 20, 1997:
The computer on the spacecraft is a single-board, single chip, rad-hard 
implementation of IBM's RS/6000 architecture.  The tool-chain used is 
IBM's XLC  compiler.

We are flying VxWorks, from Wind River Systems, as our real-time operating
system.

                                                - Steve