---
name: "cgthree"
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/cgthree"
---

# cgthree(4)

8-bit color frame buffer

## NAME

**cgthree** – 8-bit color frame buffer

## SYNOPSIS

**cgthree\* at sbus?** **wsdisplay\* at cgthree?**

## DESCRIPTION

The **cgthree** is an SBus color frame buffer.

The **cgthree** driver interfaces the frame buffer with the [wscons(4)](/wscons/4.md) console framework. It does not provide direct device driver entry points but makes its functions available via the internal [wsdisplay(4)](/wsdisplay/4.md) interface.

## DISPLAY RESOLUTION

If the **cgthree** frame buffer is used as the console display, it is possible, for some models, to select a different resolution than the default 1152x900 or 1024x768 by changing the OpenPROM environment. To change the default resolution, type the following:

  *ok* setenv *output-device* screen:r1152x900x66

to change to a 66Hz 1152x900 resolution.

If the **cgthree** frame buffer is a secondary display, or a serial console is used, the display resolution cannot be changed without using an *nvramrc* OpenPROM script. Refer to the *Sun* *Frame* *Buffer* *FAQ* for details.

The **cgthree** frame buffer accepts the following resolutions:

- screen:r1024x768x77

  Super VGA 1024x768, with a refresh rate of 77Hz. This is the default setting on model 501-2691.

- screen:r1152x900x66

  Standard 1152x900, with a refresh rate of 66Hz. This is the default setting on older models (501-1415 and 501-8044).

- screen:r1152x900x76

  Standard 1152x900, with a refresh rate of 76Hz. This is the default setting on more recent models (501-1718 and 501-1909).

Note that not all models support settings other than their default setting.

## SEE ALSO

[intro(4)](/intro/4.md), [sbus(4)](/sbus/4.md), [wscons(4)](/wscons/4.md), [wsdisplay(4)](/wsdisplay/4.md) *Sun Frame Buffer FAQ*, http://www.sunhelp.org/faq/FrameBuffer.html.