A formula,
over a shell.

1. The prompt reads workstation$. A short command returns “Radio round trip: confirmed” across the radio link.
2. Run goblin-purrfect edit RADIO-MATH.WP --kitty --theme hercules.
3. Type the heading “A small link. A real workspace.” in the document.
4. Press Alt-F9, then 6, 1, 9 to open the equation editor.
5. Type the quadratic formula source below. The source arrives first, followed by the DjVu-compressed preview: a fraction, plus-or-minus sign, superscript and square root. The preview stays at its full size throughout this recording.
6. Press F7 to commit the equation, then Ctrl-S to save.

x = {-b plusminus SQRT {b^2 - 4ac}} OVER {2a}

The result is x = (−b ± √(b² − 4ac)) / (2a).

DjVu, verified
in the radio traffic.

This recording uses the updated Purrfect renderer: seven ink levels plus transparency make an eight-entry palette. Goblin Mosh’s palette-djvu-v1 capability is enabled, and the captured image messages contain DjVu data rather than WebP.

The 1040 × 336 preview carries 3,883 bytes of DjVu image data plus 32 bytes of palette data. The previous recording’s preview at the same dimensions used 5,526 bytes of WebP data. This compares the two Purrfect renderings of the same equation; the updated renderer also reduces its color palette.

From entering the formula to receiving the image took 82.9 seconds in this take. The complete recording lasts 4:05 and plays at its original speed. These are measurements of this session, not a guaranteed link speed.

How we checked
the radio path.

Both USB radios were attached to one Linux test machine. The Mosh client and its SOCKS5 radio driver ran inside a separate network namespace containing only loopback: no Ethernet, Wi-Fi, mesh IP interface, or route back to the host. That client could reach the server only through its USB radio and the second physical radio.

SSH over the existing network started the Mosh server before capture. The server listened on the receiving radio’s IP interface. A packet capture on that interface recorded Mosh traffic in both directions; the radio drivers’ transmit and receive counters also advanced. Local keystroke prediction was disabled. Purrfect used inline image data, so graphics could not pass through a shared file or shared-memory shortcut.

The editor’s “Kitty inline PNG” label describes the image it hands to Mosh. Mosh encodes that image as DjVu for the radio transfer, then the client decodes it for display. The application’s label does not describe the radio encoding.

The editor’s label “local Rust preview” describes its equation renderer running beside Purrfect on the server. The resulting image still crosses the radio to reach the viewing terminal.

Read the recording’s verification data. The two-radio test demonstrates the physical radio transport; the setup guide shows how to use it with separate Mac and Linux computers.

Back to the video · Download the MP4 · Set up Mosh across goTenna