MOVE "e:" IN "CPMstuff"

Attempting to mount a drive that's already assigned will produce the error Already exists, 0:1. In order to do that, you'll first need to unmount the drive with MOVE ... OUT. The syntax is even simpler:

MOVE drive OUT

So to unmount the disk image from b: we just need to give:

MOVE "b:" OUT

You cannot unmount the c: drive and attempting to do so will report an In use, 0:1 error. You can however temporarily eject it (for example to write to it or just change it to a different version of NextZXOS, or even a game). Doing that without powering down or just arbitrarily, can damage your card beyond repair so you must be VERY careful. Since the potential for damage is great, NextZXOS has a special command to address that specific need called REMOUNT. Remount is given without any parameters and upon invocation it will prompt you to:

Remove/insert SD and press Y

Once you see the message you can eject your SD card, and when you reinsert it, press Y. NextZXOS will perform the same mounting procedure it performs on boot (for all drives) and your SD card contents will be safe!

Virtual filesystem management – .mkdata and .mkswap

As we've already demonstrated, NextZXOS can read unprotected +3DOS and IDEDOS virtual disks, but how are these made? There are two ways to do it: We can either create them externally using special imaging software or right on NextZXOS, with the use of a specialised dot command called .mkdata. Its syntax is as follows:

.mkdata filespec [size]

where filespec must follow the requirements set forth in the Filenames section for legal filenames omitting the drive and size is an optional number from 1 to 16 (in Megabytes). Leaving size blank, will select the default size of 16 Megabytes. You can use ANY filename, however only filenames with a .p3d type, named as described in the automounting section earlier in this chapter and located inside c:/nextzxos/ will be automounted. Here are some examples:

To make an 8 Megabyte automountable (as a:) virtual disk:

.mkdata /nextzxos/drv-a.p3d 8

To make a 16 Megabyte virtual disk that can be manually mounted in c:/images/:

.mkdata /images/disk.p3d

In order to make a virtual disk in a different drive you need to first change to it. For example:

CD "d:"
.mkdata /images/disk.p3d

will make a 16 Megabyte virtual disk image file named disk.p3d in d:/images/.

NextZXOS also supports virtual memory in the form of virtual swap partitions. These are similar to the virtual disk images with the difference that they cannot be mounted as drives. You can make virtual swap partition images with the .mkswap dot command which follows the same syntax as .mkdata.

.mkswap filespec [size]

To make an 8 Megabyte virtual swap partition image named swp-0.p3s you will need to give: