XCON/R1

What does XCON do?

What Does It Do?

• XCON (eXpert CONfigurer) was an expert system designed to efficiently select and order mainframe computer equipment (and its associated hardware components), based on a client's specific needs and predetermined system specifications.

• This ES, complete with its set of 10,000+ logical rules, was directly responsible for nearly $25 million in yearly savings, and boasted a whopping 95-98% order accuracy rate, at the height of its use.

Primary User: DEC

Who uses it?

• XCON's original/primary beneficiary was the Digital Equipment Corporation (DEC), a now-defunct computer hardware and software production firm.

• DEC was a mainstay in the computer industry from the early 1960s to the late 1990s, until its ultimate dissolution and acquisition by Compaq in 1998.

Reasons for Using XCON

Why is it used?

• Significantly reduces the amount of time and money wasted on product returns and needless, additional component orders

• Preserves and centralizes the knowledge of industry experts; leading to a marked decrease in company costs and informational volatility

• Makes decisions much faster, and with more accuracy, than the standard capacity of human experts and technicians

• Maintains a high standard of efficiency and reliability, through the use of its built-in logic structures and error correction protocols

Internal Knowledge Base

Information

Throughout its lifetime, XCOM maintained an expansive database of the various specifications, spatial configurations, capacities, and intercompatibilities associated with the following computer hardware devices and components:

• Mainframe/CPU Cabinets
• Storage Disk/Tape Drives
• Unibus (Direct Memory Access) Modules
• Power Connectors and Internal Cables
• Peripheral Device Drivers
• Auxiliary Language and Memory Chipsets
• User Input Terminals
• Workstation Consoles, etc.

Example Logical Rule Sets (XCON's Inference Engine)

Logic Structure

According to multiple sources, XCON's decision-making architecture was written in OPS5 (a (now obsolete) production-level programming language), and bases its logic on an IF...THEN decision structure. The following rules are purely hypothetical:

• IF order includes PDP-11 minicomputer & order does not include A1000 input terminal & maximum energy budget has not been exceeded

THEN place order for A1ooo input terminal

• IF VAX-8000 has open drive slot & storage capacity is less than determined limit & X2 tape drive is compatible with VAX-8000

THEN configure and install X2 tape drive

• IF order includes Alpha AXP computer system & RK611 Unibus module & current configuration does not support dual-port disk drives

THEN place order for AXP cable package & RK611 connector bundle & Q-1 single-port disk drive & Q-1 cabling/housing assembly

Additional Links and XCON Architecture Diagram

Links and Architecture

• https://everipedia.org/wiki/lang_en/Xcon
• https://www.scribd.com/doc/40730663/XCON#
• https://www.engineeringenotes.com/artificial-intelligence-2/expert-systems/examples-of-expert-systems-artificial-intelligence/35518