go64u

Ultimate64 Remote CLI

go64u is a tool for remote interaction with the Ultimate64 computer.

go64u [command] [flags]

How to start

Option 1 - UI Mode

go64u

Option 2 - Terminal Mode (REPL)

go64u --terminal

Option 3 - CLI Mode

go64u <command>

Global Flags

Flag	Short	Type	Default	Description
`--terminal`	–	bool	`false`	Run the application in terminal (REPL) mode
`--device`	`-d`	string	(from config)	Set device. Needed in non-terminal mode

Machine Commands

`devices`

Show device configurations.

`message [message] [x] [y]`

Writes a message on screen at a given position.

`pause`

Pauses the U64 by pulling the DMA line low at a safe moment. This stops the CPU. Note that this does not stop any timers.

`poweroff`

Shuts down the U64. Note that it is likely that you won't receive a valid response.

`readmem [address]`

Reads several bytes from memory by a given length.

Flag	Short	Type	Default	Description
`--length`	`-l`	uint16	`1`	Length of data to read
`--output`	`-o`	string	`output.bin`	Output file name
`--type`	`-t`	string	`file`	Output type: `file` or `bin`

`reboot`

Reboots the U64. Re-initializes the cartridge configuration and sends a reset to the machine.

`reset`

Resets the U64. The current configuration is not changed.

`resume`

Resumes the U64 after pause. The DMA line is released and the CPU will continue where it left off.

`togglemenu`

Toggles the on-screen menu. Does the same thing as pressing the Menu button on an 1541 Ultimate cartridge or briefly pressing the Multi Button on the Ultimate 64.

`writemem [address] [value]`

Sets one byte in memory (POKE). Writes a byte value (00-ff) to a memory address (0-ffff).

Runner Commands

`crt [file]`

Loads a cartridge file into the U64 and automatically starts it. The machine resets with the attached cartridge active. It does not alter the configuration of the Ultimate.

`load [file] [address]`

Loads a program into the U64. The machine resets and loads the attached program into memory using DMA. It does not automatically run the program.

`mount [drive] [file]`

Mounts a disk image (d64/g64/d71/g71/d81) on a given drive.

`run [file] [address]`

Loads a program into the U64 and automatically starts it. The machine resets, loads the attached program into memory using DMA, then automatically runs the program.

`unmount [drive]`

Unmounts a disk image from a given drive.

File Commands

`ls [path/diskimage]`

List files of the internal drive (USB Stick, SD Card, Disk Images, etc.).

Flag	Short	Type	Default	Description
`--memaddress`	`-m`	bool	`false`	Display the start address of a program if possible
`--filter`	`-f`	string	(empty)	Filter the list by a match pattern like `*.prg`

Drive Commands

`drives`

Show drive info.

Stream Commands

`audio [command]`

Starts/Stops the audio stream.

Command	Description
`audio start`	Start the audio stream
`audio stop`	Stop the audio stream

`debug [command]`

Starts/Stops the debug stream. Audio and video streams will be stopped.

Command	Description
`debug start`	Start the debug stream (audio/video streams will be stopped)
`debug stop`	Stop the debug stream

`video [command]`

Starts/Stops the video stream.

Command	Description
`video start`	Start the video stream
`video stop`	Stop the video stream

VIC Commands

`screenmem`

Shows the current VIC states of D011/D016/D018 and the memory bank setup.

`screenshot`

Takes a screenshot of the current screen.

Flag	Type	Default	Description
`--scale`	int	`100`	Scale factor in percent (%)

Platform Commands

`info`

Show device info.

`online`

Check if the selected device is online (responds to HTTP requests).

Terminal Mode (REPL)

Terminal mode is started with go64u --terminal. It provides an interactive REPL where all standard commands are available plus the following terminal-only commands:

`asc`

Interactive audio stream controller. Lets you select from configured devices, play/stop audio streams, and switch between devices interactively.

`cd [path/diskimage]`

Change the folder on the internal drive. Only available in terminal mode because it maintains a persistent working directory across commands.

`device [device_key]`

Switch the active device within the terminal session. Shows the current device if no key is provided.

`query`

Query packages matching a filter. By default the filter is set to the current year and type=d64.

Flag	Type	Default	Description
`--name`	string	(empty)	Filter by name
`--group`	string	(empty)	Filter by group
`--handle`	string	(empty)	Filter by handle
`--category`	string	(empty)	Filter by category
`--repo`	string	(empty)	Filter by repository
`--subcat`	string	(empty)	Filter by subcategory
`--year`	string	(current year)	Filter by year
`--rating`	string	(empty)	Filter by rating
`--type`	string	(empty)	Filter by type
`--latest`	string	(current month)	Filter by latest
`--offset`	int	`0`	Result offset
`--limit`	int	`80`	Result limit
`--ignoreDefaults`	bool	`false`	Ignore default filters
`--get`	bool	`false`	Download the files

`quit`

Quit the terminal and exit the application.

`stream`

Stream to your favourite streaming platform (e.g. Twitch/YouTube). Starts both video and audio streams and pipes them through an RTMP encoder.

Flag	Type	Default	Description
`--target`	string	(empty)	Streaming platform (e.g. twitch, youtube)
`--record`	string	(empty)	Record locally: `audio`, `video`, or `both`
`--no-overlay`	string	(empty)	Disable overlay for: `stream`, `record`, or `both`

Database Sub-REPL

After entering query (or its dedicated database mode), the following sub-commands are available within the database REPL:

`category`

Show categories.

`filter`

Show/set active filters.

`list`

List filtered results.

`quit`

Leave the database sub-REPL.

GUI Frontend (Gio UI)

The graphical interface is launched without the --terminal flag and uses the Gio UI framework (gioui.org). The window has a resolution of 800x680 pixels with a dark Material Design theme.

Layout

The layout consists of three areas:

Toolbar (top) – Control buttons for the selected device
Main area – Device cards (left) + Video monitor grid (right)
Footer (bottom) – Status line with hover hints

Toolbar Functions

Button	Function
Play/Stop	Start/Stop all streams for the selected device
Pause	Pause the U64 (DMA line low)
Audio	Enable/Disable audio monitoring with playback
Video	Enable/Disable video monitoring
Snapshot	Save a screenshot as PNG to the configured folder
Record	Start/Stop MP4 recording (video + audio)
Cast	Start/Stop streaming to a platform (e.g. Twitch)
Overlay	Enable/Disable the stream overlay
CRT	Enable/Disable the CRT scanline effect
Reset	Send a reset to the U64
Power Off	Shut down the U64

Device Cards

Each configured device is displayed as a card with rounded corners. The card shows:

Device name and description
Online status indicator (green = online, red = offline, gray = unchecked)

The online check runs automatically every 5 seconds in the background.

Video Monitor

Displays active video feeds in a grid layout
Supports multiple simultaneous device streams
Native resolution: 384x272 pixels (Ultimate64)
Scaling with rounded corners
Optional CRT scanline effect (sine wave-based brightness modulation)

Audio Waveform

Real-time stereo waveform visualization
Two channels with visible gap
Updated live during audio playback

Drag & Drop (Windows)

On Windows, files can be dragged and dropped onto a device monitor window. The file is automatically routed to the correct device based on the drop position in the grid.

Recording & Streaming

Recording: Saves as MP4 to the configured RecordingFolder
Casting: Streams live to configured platforms (e.g. Twitch) via the StreamingTargets configuration
Both use the StreamRenderer for video encoding, audio mixing, and optional overlay compositing

Audio System

Framework: ebitengine/oto/v3
48 kHz sample rate, stereo, 16-bit signed LE
Real-time playback and monitoring

Screenshots

Folder structure with icons

Audio Stream Player - Terminal

Stream Player - Monitor

Installation

The app tries to find the config file first in the app folder. If this is the wrong location, create an environment variable GO64U_CONFIG_PATH where the .go64u.yaml file is located.

The structure of the file is currently as follows:

LogLevel: ffmpeg_loglevel
Devices:
  DEVICE_NAME1:
    Description: "Device Nme"
    IsDefault: true
    IpAddress: <ip of device>
    VideoPort: 11000
    AudioPort: 11001
    DebugPort: 11002
  DEVICE_NAME2:
    Description: "Device name"
    IpAddress: <ip of device>
    VideoPort: 21000
    AudioPort: 21001
    DebugPort: 21002
StreamingTargets:
  twitch: rtmp://live.twitch.tv/app/<stream_key>
  OTHER: rtmp://
ResourceUrl: http://hackerswithstyle.se/leet/search
DatabaseClient: Assembly64  
DumpFolder: <path to dump folder>
ScreenshotFolder: <path to screenshot folder>
RecordingFolder: <path to recording folder>
Overlay:
  ImagePath: <path to 1920x1080 overlay PNG with transparent stream area>
  GameX: 160
  GameY: 100
  GameW: 1536
  GameH: 1088

Note: If you have more than one Ultimate64 board, you have to choose different ports for each board.

Note: If you want to stream the U64 stream via RTMP to Twitch, YouTube, etc. you need to install ffmpeg.

Todo

List and change dir (local and remote)
Disassembler with dialect option

Name		Name	Last commit message	Last commit date
Latest commit History 217 Commits
.github/workflows		.github/workflows
commands		commands
config		config
database		database
doc		doc
fonts		fonts
gui		gui
imaging		imaging
network		network
renderer		renderer
setup		setup
streams		streams
terminal		terminal
tools/macos-cross		tools/macos-cross
util		util
.gitignore		.gitignore
.go64u.yaml.txt		.go64u.yaml.txt
C64_Pro_Mono-STYLE.ttf		C64_Pro_Mono-STYLE.ttf
README.md		README.md
build.ps1		build.ps1
build_macos.ps1		build_macos.ps1
go.mod		go.mod
go.sum		go.sum
main.go		main.go
test.png		test.png

Folders and files

Latest commit

History

Repository files navigation

go64u

How to start

Option 1 - UI Mode

Option 2 - Terminal Mode (REPL)

Option 3 - CLI Mode

Global Flags

Machine Commands

devices

message [message] [x] [y]

pause

poweroff

readmem [address]

reboot

reset

resume

togglemenu

writemem [address] [value]

Runner Commands

crt [file]

load [file] [address]

mount [drive] [file]

run [file] [address]

unmount [drive]

File Commands

ls [path/diskimage]

Drive Commands

drives

Stream Commands

audio [command]

debug [command]

video [command]

VIC Commands

screenmem

screenshot

Platform Commands

info

online

Terminal Mode (REPL)

asc

cd [path/diskimage]

device [device_key]

query

quit

stream

Database Sub-REPL

category

filter

list

quit

GUI Frontend (Gio UI)

Layout

Toolbar Functions

Device Cards

Video Monitor

Audio Waveform

Drag & Drop (Windows)

Recording & Streaming

Audio System

Screenshots

Folder structure with icons

Audio Stream Player - Terminal

Stream Player - Monitor

Installation

Todo

About

Topics

Resources

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Stars

Watchers

Forks

Releases 2

Packages 0

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Contributors

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`devices`

`message [message] [x] [y]`

`pause`

`poweroff`

`readmem [address]`

`reboot`

`reset`

`resume`

`togglemenu`

`writemem [address] [value]`

`crt [file]`

`load [file] [address]`

`mount [drive] [file]`

`run [file] [address]`

`unmount [drive]`

`ls [path/diskimage]`

`drives`

`audio [command]`

`debug [command]`

`video [command]`

`screenmem`

`screenshot`

`info`

`online`

`asc`

`cd [path/diskimage]`

`device [device_key]`

`query`

`quit`

`stream`

`category`

`filter`

`list`

`quit`

Packages