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SmartPort Hard Drives

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Mike Daley edited this page Aug 2, 2026 · 1 revision

SmartPort Hard Drives

The SmartPort card gives the emulator hard drive volumes -- a ProDOS disk large enough not to think about, instead of swapping 140KB floppies. Open View > SmartPort Drives to manage them.

Table of Contents

Requirements

A SmartPort card must be installed. By default it is in slot 7. If the window reports that no card is present, open View > Expansion Slots and drag SmartPort into slot 2, 4, 5 or 7.

The card provides two block devices, shown in the window as two drive bays.

Image Formats

Extension Notes
.hdv Raw ProDOS-ordered blocks. The most common hard drive image format.
.po ProDOS-ordered; the same layout, usually used for floppy-sized images.
.2mg A 64-byte header followed by block data. The header is parsed and honoured.

Images can be far larger than a floppy -- ProDOS supports volumes up to 32MB, and the usual convention is one 32MB volume per device.

Inserting an Image

Three ways:

  • Drag and drop an image file onto a drive bay.
  • Click a bay to open a file picker.
  • Use a link -- ?hd= and ?hd2= insert images from a URL when the page loads. See URL-Parameters.

Recently used images are remembered and can be re-inserted from the recents list without browsing for them again.

Booting from a Hard Drive

With a bootable ProDOS volume in the first device, the machine boots from the SmartPort card if it takes boot priority. From the BASIC prompt you can also boot a specific slot:

PR#7

(Substituting whichever slot holds the card.) If a floppy is in drive 1 of the Disk II controller, that will normally win at power-on, so eject it first if you want the hard drive to boot.

Persistence

Hard drive images and any writes made to them are stored in the browser's IndexedDB and restored on reload, so a volume you installed software onto is still there next session.

Images loaded from a URL are deliberately transient: they are not saved to storage or added to recents, and autosave is suspended for that session so a shared link cannot quietly overwrite the persisted image. See URL-Parameters.

How It Works

The card implements the SmartPort protocol -- STATUS, READBLOCK, WRITEBLOCK, FORMAT, CONTROL and INIT -- together with the older ProDOS block-device entry point, so software using either convention works.

Unlike the other cards, the SmartPort card builds its own ROM at runtime rather than loading a dump: the firmware is small, and generating it avoids shipping a ROM image whose provenance would be unclear.

Blocks are 512 bytes. The card reports its device count and each volume's block count through STATUS, which is how ProDOS discovers the volumes at boot.

See Also

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