---
name: "tsc"
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/tsc/4"
---

# tsc(4)

DECchip 21272 and 21274 Core Logic chipset

## NAME

**tsc**, **tsp** – DECchip 21272 and 21274 Core Logic chipset

## SYNOPSIS

**tsc\* at mainbus?** **tsciic\* at tsc?** **tsp\* at tsc?** **pci\* at tsp?**

## DESCRIPTION

The **tsc** driver provides support for the DECchip 21272 (Tsunami) and 21274 (Titan) Core Logic chipsets found on most 21264-based systems.

The **tsp** driver attaches to it and provides support for the DECchip 21272 and 21274 built-in PCI controller.

DECchip 21272 provides one PCI bus, while DECchip 21274 provides two distinct PCI buses, the second one with AGP capabilities.

## SEE ALSO

[intro(4)](/intro/4.md), [pci(4)](/pci/4.md), [tsciic(4)](/tsciic/4.md)

## BUGS

The AGP capabilities of the second PCI bus of DECchip 21274 are not currently supported.