SD cards and hard disks

Media > SD Card holds the card of a machine with an SD card slot, and Media > Drives the hard disks of a machine with an IDE interface. Either can be an image file or a folder of your computer. The divMMC’s cards are in divMMC.

SD card

The two ZX Evolution machines and the ZX Spectrum Next have an SD card slot. The Next starts from a card with System/Next on it, and its menu has System/Next Card… too: see The SD card. Media > SD Card shows the card in the slot, or (no card), and has:

  • Open Image… - insert a card from an image file.

  • Open Folder… - use a folder on your computer as the card. See A folder as a disk.

  • Eject - take the card out.

  • Refresh - a folder card only: files added, changed or deleted in the folder reach the machine while it runs. See Refresh.

  • Write Protect - the card’s lock switch: the machine cannot write to the card. On a folder card it makes that one folder read only.

What the machine writes to a card image goes into the image file at once. To start with a card, use --sdcard <file or folder> on the command line.

Hard disks

A machine with an IDE interface (see Which machine has what) has two places for a drive, Master and Slave. Connect them first: on the Machine page of Options, click the gear in the Hard disk row and set Master (and Slave, if you want two) to HDD (ATA).

Media > Drives then has a submenu for each connected device, named Master: or Slave: followed by the name of the image in it:

  • Open Image… - open a hard disk image: .hdi, or a plain image of the disk with any other extension.

  • Open Folder… - use a folder on your computer as the disk. See A folder as a disk.

  • Eject - take the image out.

  • Refresh - a folder disk only, as on an SD card: see Refresh.

  • Properties… - the window Hard Disk: Master (or Slave): the image, its cylinders, heads and sectors (C / H / S), its Capacity, and the LBA box. LBA lets the system address the disk by sector number; clear it for an old system that only knows cylinders, heads and sectors.

What the machine writes to a hard disk image goes into the file at once. The images stay mounted when you switch machines, and are opened again at the next start.

A folder as a disk

Open Folder… in Media > SD Card, in a divMMC’s card menus and in Media > Drives lets the machine use a folder of your computer as if it were a FAT32 card or disk. There is no image to make: copy programs into the folder and open it. The window that picks the folder is Folder to serve as the card or Folder to serve as the disk. How the disk is made and written back is in A folder as a disk of Under the Hood.

  • The folder is read when it is opened, and again at Machine > Reset > Hard Reset and when you switch machines; Apply in Options does not read it again. To bring in files added, changed or deleted since without a reset, use Refresh (see Refresh).

  • The disk is made big enough for the folder, from 512 MB up to 32 GB. A folder that takes writes gets as much free room again as its files take, and 256 MB more. A larger folder is not opened, and the message folder too big for a disk says so.

  • These are left out: files of 4 GB and over, folders more than 16 levels deep, entries past 65536 in one folder, and anything past 200000 entries in all. The message folder: not all of it fits says when something was left out.

  • A link to a folder (a junction on Windows) is followed once: one that leads back into the folder, or to a place already shown, is left out. A Windows shortcut (.lnk) is a file like any other; files your system hides are left out.

  • A folder is not a whole disk: attributes, dates other than the last write and sectors outside files last only until the folder is read again (see What a folder cannot do). For full compatibility, use an image.

  • On a hard disk, a folder that holds NedoOS with its ZXLDR file in the top level can boot NedoOS.

Writing to a folder

A folder takes what the machine writes: a program it saves, a file it changes or deletes there changes the files in the folder itself. The folder follows about half a second after the machine stops writing. A file the machine saves with no date keeps the time it was written on your computer.

The first time the machine writes to a folder, it stops and Writing to a folder asks:

  • Allow writing - the folder takes this write and every one after it.

  • Read-only - the folder stays as it is. What the machine wrote stays in memory, and the machine sees it, until the folder is read again. Folders opened after that are read only.

It asks once: the answer becomes the Folders setting. Both settings are in the Folder as a disk group on the Emulation page page of Options:

  • Folders - R/W, read/write (the default), or R/O, read-only. The machine cannot write to a folder opened read-only: esxDOS reports I/O ERROR, a hard disk an error. R/O takes effect at Apply: a folder in use stops changing, and what the machine writes to it from then on stays in memory, as with the Read-only answer above. R/W takes effect when the folder is next read: at a Hard Reset or a change of machine.

  • Deleted files - Move to trash (the default) puts a file the machine deletes in your system’s trash; Delete permanently removes it. A file the trash will not take stays in the folder.

Write Protect in a card’s menu makes that one folder read only, whatever Folders says.

What the machine wrote is never thrown away on the way. When something cannot be carried over - a file another program has open, a name your system refuses - a message says so once, naming the files, and a file’s content that could not be put in its place is kept in the folder’s top level with (recovered) in its name. A file you change on your computer while the machine has the folder keeps your change: the machine’s version is saved beside it as name (2), and the machine deleting it leaves it where it is.

Keep a copy of anything you cannot afford to lose. Formatting the card or disk, or deleting most of the folder at once, does not reach your files: the folder is left alone from then on, what the machine writes stays in memory, and a message says so.

Refresh

Refresh in a folder card’s or folder disk’s menu brings in what you changed in the folder since it was read: new files and folders, changed files, deleted ones. The machine keeps running and needs no remount, unlike a real card put back. What the machine wrote there first goes to the folder. The message refreshed: 2 new, 1 gone, 0 changed says what changed.

The machine sees the change the next time it reads the folder: esxDOS at its next listing, the NextZXOS Browser when it shows the folder again (leave it and come back). Files that stayed keep their place on the disk, so a file the machine has open, a disk image it has mounted and the folder it is in read on as before.

Refresh is refused, with a message, when what the machine wrote has not all reached the folder, when the folder no longer follows the machine, or when the changes do not fit on the disk; Eject and Open Folder… then read the folder anew. An image file has no Refresh. A changed ZXLDR boots only after a Hard Reset.

Two hotkeys, with no key until you give them one, work on SD cards from the keyboard: SD Card: Refresh refreshes every folder card the machine uses, and SD Card: Eject takes out the machine’s card - the slot’s on the ZX Evolution and the Next (where the Next’s own card goes back in), the card in the divMMC’s first filled slot on the others.