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SD Card Utility tab

Julien Clauzel edited this page Jul 25, 2026 · 2 revisions

The SD Card Utility tab

In one line: open a Spectrum Next SD card image on your PC, copy files in and out of it with a two-pane file explorer, then boot it in an emulator.

This is the tab for emulator users and developers. A Spectrum Next SD card image (an .img or .hdf file) is a single file that contains everything the machine needs to boot — think of it as an ISO. Normally you would need command-line tools to get files into one. Here you drag them across.

If you own real hardware and want to send files over Wi-Fi instead, you want the NextSync tab.

The SD Card Utility tab

Your PC on the left, the inside of the SD card image on the right, the log window below, and the emulator launchers at the bottom. The log is shown in 🎮 Retro mode.

Before you start

This tab needs hdfmonkey, a small external tool that does the actual reading and writing inside the image. Without it the right-hand explorer stays empty and the log window says so.

If it is missing, a Download and install HDF Monkey button appears at the bottom right — click it and the app fetches a build for your platform. The better route is to install CSpect from the itch.io tab, which bundles hdfmonkey too. Full details: Installation → hdfmonkey.

Quick start

  1. Get an image. Click Download NextZXOS Image to fetch a ready-to-use NextZXOS card from zxnext.uk — it downloads, saves, and loads itself automatically. If you already have one, click Select Disk Image and browse to it instead.
  2. Wait for the right pane to fill. That is the inside of your image. The gauge underneath shows how full it is.
  3. Find your files in the left pane, which is your PC.
  4. Copy them across. Select them and click ->:, or just drag them from the left pane to the right one.
  5. Launch it. Click 🕹 Launch CSpect (or Launch Mame) at the bottom. The emulator boots your image with the files you just added.

The screen at a glance

┌────────────────────────────────────────────────────────────────────┐
│ [ SD card image path ▾ ] [Select Disk Image] [Download NextZXOS…]   │
│ [C:▾]  Search: [ filter ]                        Filter: [ filter ] │
├───────────────────────────┬───┬────────────────────────────────────┤
│ Up  Refresh  Local path:  │   │ Up  Refresh  Disk Image Explorer:  │
│                           │->:│                                    │
│    your PC's files        │   │      files inside the image        │
│                           │:<-│                                    │
│                           │   │ [▓▓▓▓▓░░░░] image usage gauge      │
│                           │   │ [New Folder] [Rename] [Delete]     │
├───────────────────────────┴───┴────────────────────────────────────┤
│ log window                                              [🎮 Retro] │
├────────────────────────────────────────────────────────────────────┤
│ ┌─ MAME ──────────────┐  ┌─ CSpect ────────────────────────────┐   │
│ │ Launch Mame  ▾ ▾ ▾  │  │ Launch CSpect  ▾ ▾ ▾ ▾ ▾ ▾ ▾        │   │
│ └─────────────────────┘  └─────────────────────────────────────┘   │
└────────────────────────────────────────────────────────────────────┘

The divider between the explorers and the log window is a splitter — drag it to give either side more room.

Choosing an image

Control What it does
SD card image path Type a path directly, or click the arrow for a dropdown of images you've loaded before. Press Enter to load.
Select Disk Image Opens a file browser to pick an .img / .hdf file.
Download NextZXOS Image Downloads a ready-made NextZXOS card image from zxnext.uk, saves it, and loads it. The easiest way to get started.

The two explorers

The left pane is your PC; the right pane is the inside of the image. Both work the same way: double-click a folder to enter it, double-click .. to go back up, or use the Up and Refresh buttons. The path box above each pane shows — and accepts — the current folder.

On Windows a drive letter dropdown sits at the top left for switching between C:, D: and so on.

Two filter boxes narrow what you see as you type: Search: filters the local pane by name, Filter: filters the image pane by name, type or size. Clear the box to see everything again.

Moving files

Three ways, all equivalent:

  • The arrow buttons. Select items, then ->: copies PC → image, and :<- copies image → PC.
  • Drag and drop, in either direction. You can also drag files straight in from Windows Explorer / Finder / your file manager.
  • Copy and paste. Ctrl+C / Ctrl+V work between the panes and with your operating system's clipboard.

Transfers run in the background with a progress dialog, so a large copy will not freeze the app.

Managing files inside the image

The New Folder, Rename and Delete buttons under the right pane act on whatever is selected. Right-clicking gives you more:

Right-click on the image pane
New Folder Here… Create a folder inside the selected folder
Copy / Cut / Paste Move things around inside the image, or across from your PC
Rename… / Delete Act on the selection (multi-select works — the menu says "Delete 3 items")
Remote Unzip file Unpack a .zip that is already inside the image
Remote Zip Archive the selected items into a .zip inside the image

The local pane's right-click menu adds Copy text to clipboard, Copy path to clipboard, Zip and Unzip file to the same basics.

Note on Zip/Unzip inside the image: there is no unzip program running on the image, so the app stages the work on your PC (extract or compress locally, then copy the result back). It is transparent, just not instant.

The usage gauge

The bar under the image explorer shows how full the card image is. When it gets close to full the app warns you before a transfer — you can turn that warning off with "SD Card - Warn when an image is nearly full" in Settings.

Launching an emulator

Two groups sit at the bottom of the tab. Each has a launch button plus dropdowns whose values are passed to the emulator on the command line, so you never have to remember its options. Every choice is saved.

CSpect

Control Options
🕹 Launch CSpect Boots the currently loaded image
Screen size X1 … X4 (defaults to X3)
Sound on / off
VSync on / off
Joystick on / off
Mouse capture on / off
Frequency display refresh rate
ESC key Disable ESC Key On (default) stops ESC from quitting instantly

CSpect is .NET-based, so Linux and macOS also need Mono — see Installation → Mono. On Windows, sound needs OpenAL.

MAME

The MAME group shows ⬇ Install MAME instead of a launch button when MAME isn't found. On 64-bit Windows that button detects the latest official release and installs it into downloads/mame (about a 90 MB download). On Linux and macOS you install MAME yourself and the app detects it.

Once installed, the launch button appears alongside dropdowns for aspect ratio, sound backend, mouse (Kempston), joystick and the ESC key (which defaults to requiring a quit confirmation). MAME also needs the Spectrum Next boot ROM — see Installation → MAME.

The log window

Everything the tab does is reported here, newest first: images loaded, transfers, hdfmonkey errors, update checks. If an action seems to do nothing, read the log. The 🎮 Retro button turns it into an animated 8-bit console (needs pygame-ce).

Troubleshooting

The right pane stays empty. hdfmonkey is missing or cannot read the image. Check the log window, then Installation → hdfmonkey.

A downloaded file won't come back out of the image. Filenames with special characters — single quotes especially — can fail to download. Rename it inside the image first.

The launch button for my emulator isn't there. It only appears when the app finds the emulator. See Installation → Optional components.


See also: NextSync tab for real hardware · Settings tab for deletion prompts, colours and warnings · User Manual for the shortcuts that work in every explorer.

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