---
name: "runway"
section: "4"
platform: "openbsd"
package: "man"
version: "8.0-current-20261101"
release: "OpenBSD 8.0-current (2026-11-01)"
platforms: ["openbsd"]
url: "https://new.carta.tech/runway"
---

# runway(4)

Runway bus

## NAME

**runway** – Runway bus

## SYNOPSIS

**uturn\* at mainbus?**

## DESCRIPTION

The **runway** bus is a CPU and memory bus on systems based on the PA-7200, PA-8000, and later CPUs. The **runway** bus is a 64-bit multiplexed address/data bus with support for cache coherency and allows up to 4-way SMP system configurations.

One or two [uturn(4)](/uturn/4.md) bridges connect the **runway** bus to the system's [gsc(4)](/gsc/4.md) or [pci(4)](/pci/4.md) buses.

## SEE ALSO

[cpu(4)](/cpu/4.md), [dino(4)](/dino/4.md), [gsc(4)](/gsc/4.md), [intro(4)](/intro/4.md), [pci(4)](/pci/4.md), [uturn(4)](/uturn/4.md)

## HISTORY

The **runway** driver first appeared in OpenBSD 3.7.