### Working With Floppies

The Diskette menu shows all 4 floppy drives and what disk image is inserted in them or `<empty>` if there is none. Any disk file name enclosed in `<< .. >>` is a built-in disk image. If the name has an asterisk (`*`) before it the disk has been modified and must be saved. For non-internal disk images the changes are saved automatically, but changes to internal disk images or disk images loaded from .zip archives must be explicitly saved to another file. trs80gp will remind you to do this if you try to eject a disk with changes or exit the emulator with unsaved changes.

All built-in disk images have a short name that starts with a colon. This is displayed in parenthesis on each entry in the "Insert disk..." menu as a reminder that the short name can be used on the command line to insert the floppy when starting trs80gp.

Each drive has a sub-menu that lets you eject diskettes, replace diskettes, insert diskettes, save them to a new file or toggle their write protection. This isn't the read-only flag of the PC file system but an internal one corresponding to the physical write protect notch on the real floppy disks. Besides saving a copy of a disk image file, Diskette → ... → Export... can write out the disk image in ASCII format or as a track dump in ASCII format for debugging purposes.

The internal diskettes `unformatted dmk` and `unformatted imd` are single-sided unformatted diskettes in `DMK` and `IMD` format. Equivalent to the `-d dmk` and `-d imd` command line options. Your currently running DOS will need to format them before they can be used. `unformatted dmk DS` and `unformatted imd DS` are double-sided disk images also accessible from the command line as `-d dmk-DS` and `-d imd-DS`.

The `-d0, -d1, -d2, -d3, -td and -ld` command line options allow you to select disks to insert into the floppy drives when the emulator starts. The default is to put a TRS-DOS floppy in drive `:0` so that the TRS-80 will boot into TRS-DOS (which is the same as the `-td` option). You can just use `-d file.dsk` to have a floppy disk inserted in the next available drive or just the name of the floppy disk image if it ends in one of the known suffixes (`.dmk`, `.dsk`, `.imd`, `.hfe`, `.jv1` or `.jv3`).

Whenever a floppy is accessed trsg80p will go into turbo mode automatically. This can be enabled or disabled with the Diskette → Auto Turbo menu. Running in turbo mode has no harmful effect on diskette usage as the necessary relative timing remains the same. Generally you'd only want to turn the feature off to experience the original pace of the machine or when faster disk operations make it hard to read text. Or to keep the TRS-80's real time clock in sync with the current time.

Unlike actual floppy drives, the emulated drives operate in a special any-sided mode. If a double-sided disk image is inserted, the drive will become double-sided. If the drive has a single-sided disk image and the operating system attempts to format a track on side 2, the drive and disk image will automatically upgrade to double-sided.

To control this behaviour, the The `-dNss`, `-dNds` and `-dNas` command line options allow you to force drive N in the system to behave as single-sided, double-sided or any-sided. Alternatively, you can enable or disable any-sided mode via the Diskette → Drive → Emulate only ... menu option.

Because of problems with CP/M auto-detecting drive sides during FORMAT, the any-sided drive behaviour is not the default on the Model II family. The index hole position is different between single and doubled sided 8" diskettes. Real 8" double-sided disk drives use the position change to actively detect doubled-sided or single-sided diskettes. As a result (unless `-dNas` is used), the emulator will signal `NOT READY` from the 8" drive in the follow cases:

- Double-sided image used in a single-sided drive
- Access the second side of single-sided image in a double-sided drive

Note that in this strict mode if you wish to format a double-sided disk image you must insert a double-sided blank as the single-sided blank will not be promoted to double-sided.

Like the original machines, the Model II (`-m2`) will have single-sided 8" drives and the Models 12, 16, 6000 and Tandy 10 (`-m12 -m16 -m6000 -m10`) will have double-sided 8" drives.

#### Internal Floppy Images

A handy table listing all the available internal floppy image files and how they may be accessed from the command line. trs80gp only shows floppies made for the current model in the menu which is generally helpful but you can't use them to boot a Model 4 with a Model III TRSDOS like `trs80gp -m4 :td3` will do from the command line. Unless you export the internal `:td3` image to a file in Model III mode and then insert that file in Model 4 mode.

Model | DOS | Menu Entry | Type | Command Line
--- | --- | --- | --- | ---
I | TRSDOS 2.3 | << TRSDOS23.dmk >> | Boot | :td1 or -td
<< m1-trsdos-blank.dmk >> | Blank | :tb1
<< m1-trsdos-util.dmk >> | Utilities | :tu1
<< TRSDOS2.3jp.dmk >> | Boot | :tj1 `-m1j` default
LDOS 5.3.1 | << ld531-1.dsk >> | Boot | :ld1 or -ld (also inserts :ld1e)
<< ld531-2.dsk >> | Extras | :ld1e
<< m1-ldos-blank.dmk >> | Blank | :lb1
<< m1-ldos-util.dmk >> | Utilities | :lu1
<< ld531-1j.dmk >> | Boot | :lj1 `-m1j` for `-ld`
II 12 16 6000 | TRSDOS 2.0a | << TSDOS20A.IMD >> | Boot | :td2 or -td
<< m2-trsdos-blank.dmk >> | Blank | :tb2
<< m2-trsdos-util.dmk >> | Utilities | :tu2
LS-DOS 6.3.1a | << l2-631a.dmk >> | Boot | :ld2 or -ld
<< m2-lsdos-blank.dmk >> | Blank | :lb2
<< m2-lsdos-util.dmk >> | Utilities | :lu2
TRSDOS II 4.2 | << m2-trsdos4-blank.dmk >> | Blank | :t4b2
<< m2-trsdos4-util.dmk >> | Utilities | :t4u2
III | TRSDOS 1.3 | << TRSDOS13.DSK >> | Boot | :td3 or -td
<< m3-trsdos-blank.dmk >> | Blank | :tb3
<< m3-trsdos-util.dmk >> | Utilities | :tu3
LDOS 5.3.1 | << ld3-531.dsk >> | Boot | :ld3 or -ld
<< m3-ldos-blank.dmk >> | Blank | :lb3
<< m3-ldos-util.dmk >> | Utilities | :lu3
4 | TRSDOS 6.2.1 | << TRS621.DSK >> | Boot | :td4 or -td
<< m4-trsdos-blank.dmk >> | Blank | :tb4
<< m4-trsdos-util.dmk >> | Utilities | :tu4
LS-DOS 6.3.1 | << ld4-631.dsk >> | Boot | :ld4 or -ld
<< m4-lsdos-blank.dmk >> | Blank | :lb4
<< m4-lsdos-util.dmk >> | Utilities | :lu4
Tandy 10 | ADOS | << ados-system.imd >> | Boot | :ad
<< ados-blank.imd >> | Blank | :adb
CoCo | DECB 1.1 | << mc-dos-blank.dmk >> | Blank | :cb
Any | Any | << Unformatted dmk >> | Unformatted | :dmk
<< Unformatted imd >> | Unformatted | :imd
<< Unformatted dmk DS >> | Unformatted | :dmk-ds
<< Unformatted imd DS >> | Unformatted | :imd-ds

Type | Description
--- | ---
Boot | Boot floppy for the given DOS. Must go into drive `:0`
Blank | Formatted floppy for the given DOS.
Utility | Utility programs for copying files to and from emulated floppies.
Unformatted | Floppy image without any data. Will require a `FORMAT` before it can be used by a particular DOS.
Extras | Second floppy for Model I LDOS which doesn't have the space for everything on a single floppy.