Mobile UI

Mobile Connections




What is a terminal?

A terminal app lets you control a computer using nothing but text. This interface was the norm before mice and windows appeared in the eighties. Terminals are still essential in fields like technology and science.

How do I use a terminal?

Terminals are an advanced topic, but you can pick up the basics quickly.

Here are some good learning resources:


What emulator does Cathode use?

Cathode uses its own proprietary VT220 emulation library with behavior comparable to, iTerm, xterm, rxvt, etc.

What character sets are supported?

Cathode always works in unicode with UTF-8 encoding.

Supported symbols include Latin, Cyrillic, Greek, Armenian, Hebrew, and Math.

Double-width symbols (Chinese, Japanese, Korean, Arabic) are not supported.

What’s the difference between the desktop and mobile versions?

The iOS app creates remote sessions over SSH, while the Mac app creates local sessions.

The desktop version has a few additional features, such as: enhanced effects, themes, and text editing.

What’s Blinky and how does it differ from Cathode?

Blinky is a text-editor-only version of Cathode aimed at non-technical users. Cathode can do everything that Blinky can, so there’s no reason to buy both.

Mobile UI

Which gestures are available?

  • Tap – Show keyboard or toggle toolbar
  • Tap near top – Toggle toolbar
  • Pan – Scroll
  • Pan along right edge – Adjust scrollbar
  • Swipe from left edge – Go back
  • Pinch and zoom – Scale text
  • Double tap – Select word
  • Press, hold, and drag – Select by word

How can I choose favorite keys on the virtual keyboard?

The keyboard buttons in the center of the top row are customizable. Press and hold one until it highlights, then press any other key to copy its character.

How do I use a Bluetooth keyboard?

You can connect or disconnect a keyboard in the Bluetooth section of the Settings app.

When Cathode detects a hardware keyboard, it will hide the on-screen keyboard.

Mobile Connections

How do I enable connections on a Mac?

On the Mac, open System Preferences and go to the Sharing pane. Make sure the button next to “Remote Login” is checked, and note the IP address to the right.

How do I enable connections on a Linux machine?

The exact steps depend on your particular distribution. You’ll need to make sure an SSH server is installed and running. Here are some instructions for Ubuntu.

How do I enable connections on a Windows machine?

Windows doesn’t include an SSH server so you will need to install a third party option. Wikipedia has a helpful article comparing the choices.

How do I connect?

First, enable connections on the destination machine, as explained above.

Next, go to Cathode’s initial screen on your iOS device. If the destination server is close and it supports zero-config networking, it will appear in the “Nearby” section. Otherwise, you’ll need to create a new bookmark with the server’s name or IP address.

The following fields are available:

  • Title – A nickname. Not sent to the server.
  • Server – The network name or IP address of the server.
  • Port – Usually 22.
  • User – A username on the server.
  • Password – A password for the user (or key).
  • Key – An optional, private SSH key.
  • Identifier – Usually xterm-256color or xterm.

Once you’ve filled in the details, press “New Session”.

Can I use SSH keys?

Yes, there’s an optional field for private SSH keys. RSA or DSA keys can be added by pasting, or using iTunes file sharing.

Can I login to my iOS device directly?

iOS doesn’t allow direct shell access, but it may be possible if you jailbreak and/or install additional components.

Can I use the telnet protocol?

No. Cathode only works over SSH.


Will Cathode work on my older Mac?

Any Pro Macs or iMacs made since 2007 will perform very well.

For MacBooks, MacBook Airs, and Mac minis, the cutoff is mid-2008.

Please note the following older graphics cards are not supported:

  • Intel GMA 950
  • Intel GMA X3100
  • ATI Radeon X1600
  • ATI Radeon X1900

How can I minimize CPU and battery usage?

There are many ways to control performance:

  • Set the rendering quality (low, medium, or high).
  • Lower the frame rate.
  • Turn down some effects to zero.
  • Disable retina resolution.
  • Increase the font zoom.
  • Make windows smaller.

Purchasing Options

Can I try Cathode for free?

There’s a free demo for the Mac, but not for iOS.

Can I buy Cathode outside the Mac App Store?

Yes, you can buy an independent license with a credit card or PayPal. Here’s the link.

How does the independent license work?

After purchasing, you’ll receive an email with a unique license file. Drag and drop this file on top of to unlock it. If you’re an individual with multiple computers you can use a single license with them all.

The license is stored at /Users/username/Library/Application Support/Cathode.

Why haven’t I received my license email?

Sorry! Occasionally a license email gets blocked on the way to its destination.

Check your spam folder. If you don’t find anything, email us and we’ll respond ASAP.