Yann Serra Tutorial

The following is a getting started guide contributed by Yann Serra

Greaseweazle is a hardware and software solution that lets you archive or regenerate old floppy disks. Reading them is useful for recovering old data or forgotten programs that you can use in your favourite emulators. And writing them is useful for collectors who need real boot, game or application floppy disks to run authentic machines from the 70s, 80s and 90s.

To start, you obviously need a Greaseweazle board, since the gw software provided here runs with it only. See where to purchase a Greaseweazle board.

Then, you need some floppy drives.

Compatible with any standard floppy drive

The Greaseweazle board is compatible with any Shugart or IBM standard floppy drive, that includes any 3.5 and 5.25-inch drive with a 34-pin connector, or a 3-inch "Amstrad" drive with a 26-pin connector (actually just a shorten 34-pin connector: same signals on same pins, just the no-signal pins are missing), or a 8-inch drive with a 50-pin connector (extended 34 pin connector with irrelevant signals). You need an extra adaptor to connect 26-pin or 50-pin drives to the Greaseweazle’s 34-pin connector.

Commodore (excluding Amiga) and Apple drives (including Macintosh), which use a proprietary connection, are not supported. But you can read/write Commodore 8-bit and Apple II/Mac floppy disks with any regular 34 pin drives.

Two IBM drives, or three Shugart drives supported on the same cable

The Greaseweazle solution supports two IBM drives or three Shugart drives on the same cable.

If the drives are of "IBM" standard (any drive coming from a MS-Dos/Windows machine), then you use a ribbon cable with a twist: the drive on the edge will be drive A, and the drive in the middle connector will be drive B.

If your drives are Shugart standard from any computer before mid-90's (Amiga, Atari, Acorn…), then you use a flat ribbon cable, and tells which drive is unit # 0, 1 or 2 by moving their configuration jumpers accordingly (located near their rear, where it’s written “DS0/DS1/DS2…”).

See here for a more in-depth explanation of how to connect them.

Three levels of access for reading or writing any floppy disk

Depending on the disk image you wish to create (from a floppy disk) or restore (to a floppy disk), the Greaseweazle solution can access three levels of information on a floppy disk: the user content in the sectors, the formatted tracks, or the flux of polarised information on the surface.

Sectors: a floppy disk is made up of tracks, themselves subdivided into sectors, which contain the data directly accessible to users. It is this data that makes up the content of disk images in block mode (.img, .st, .dsk, .adf...).

Formatted tracks: for each floppy disk format, the tracks contain a particular number of sectors, of a particular size, with a particular identification in some headers, and gaps of a certain size between all these elements. In some case, there are also intentional identification errors as a form of copy-protection. All these details are stored in 'meta' images (.edsk, .imd...) that can tell which floppy disk format they contain. It matters, for instance, in case of Amstrad or CP/M computers that use several formatting variants.

Flux: Information is encoded in the form of magnetic pulses on the surface of floppy disks. Disk images such as .scp or .hfe store these pulses regardless of the encoding used, thereby preserving an exact copy of an original floppy disk, even with its intentional encoding errors that constituted the most advanced copy protections.

How to use it, level #1: the simplest/new-comer way

After having downloaded and installed the gw command line (it's just Python3 code, so it works on every modern system, including Raspberry Pis), you backup a physical disk to an image file with :

gw read --format=<profile.of.your.floppy.disk> <name_of_your_image.suffix> --drive=<ID>

For example:

gw read --format=amiga.amigados MyAmigaDisk.adf --drive=A

…will backup the physical Amiga disk you inserted into the drive, that is located at the end of your twisted cable, to a file named “MyAmigaDisk.adf”, in the current directory.

In some circumstances, you can omit the --format and the --drive options. For instances, the drive A being the default choice, and .adf disk images being most often a backup of an Amiga 880KB disk format, you can type here:

gw read MyAmigaDisk.adf

To generate some content to a physical disk from a disk image, you just replace the “read” argument with “write”, like this:

gw write --format=amiga.amigados MyAmigaDisk.adf --drive=A

In the above commands, what you tell after the “--format=” option is just the name of a predefined profile matching one of the many software formats that computer brands defined for their disks systems. Thanks to this profile, the gw command can check the content is read or written without error.

You should also take care about the suffix you put as the extension of your image name (“.adf”, for instance), as it defines the preferred disk image format for the floppy disk you are working with.

Here are some tables that would help you to find which predefined profile you should use for the floppy disk format you want to backup to disk image or to recreate from a disk image. And also, the preferred suffix your disk image should have according to the profile.

3.5-inch disks	profile	sides	cyls	RPM	kbit/s	sct/trk	byt/sct	encoding	size (KB)	suffix
Acorn BBC	acorn.adfs.320	1	80	300	250	16	256	MFM	320	.adm
	acorn.adfs.640	2	80	300	250	16	256	MFM	640	.adl
Archimedes	acorn.adfs.800	2	80	300	250	5	1024	MFM	800	.adf
RiscPC	acorn.adfs.1600	2	80	300	500	10	1024	MFM-HD	1600	.adf
Amiga	amiga.amigados	2	80	300	250	11	512	AMFM	880	.adf
	amiga.amigados_hd	2	80	300	500	22	512	AMFM-HD	1760	.adf
Atari ST	atarist.360	1	80	300	250	9	512	MFM	360	.st, .msa
	atarist.400	1	80	300	250	10	512	MFM	400	.st, .msa
	atarist.440	1	80	300	261	11	512	MFM	440	.st, .msa
	atarist.720	2	80	300	250	9	512	MFM	720	.st, .msa
	atarist.800	2	80	300	250	10	512	MFM	800	.st, .msa
	atarist.880	2	80	300	261	11	512	MFM	880	.st, .msa
C64/C128	commodore.1581	2	80	300	250	10	512	MFM	800	.d81
IBM PC	ibm.720	2	80	300	250	9	512	MFM	720	..img
(Sam Coupé)	ibm.800	2	80	300	250	10	512	MFM	800	.img, (.mgt)
(Macintosh HD)	ibm.1440	2	80	300	500	18	512	MFM-HD	1440	.img, (.dsk)
	ibm.1680	2	80	300	500	21	512	MFM-HD	1680	.img
	ibm.dmf	2	80	300	500	21	512	MFM-HD	1680	.img
	ibm.2880	2	80	300	1000	36	512	MFM-ED	2880	.img
Macintosh 68K	mac.400	1	80	VAR	375	12-8	512	GCR	400	.dsk
	mac.800	2	80	VAR	375	12-8	512	GCR	800	.dsk
MSX	msx.1dd	1	80	300	250	9	512	MFM	360	.dsk
	msx.2dd	2	80	300	250	9	512	MFM	720	.dsk
Nec PC98	pc98.2hs	2	81	300	500	9	1024	MFM-HD	1458	.hdm, .xdf
Piano	akai.800	2	80	300	250	5	1024	MFM	800	.img
	akai.1600	2	80	300	500	10	1024	MFM-HD	1600	.img
	ensoniq.mirage	1	80	300	250	5+1	1K+512	MFM	440	.img
	ensoniq.800	2	80	300	250	10	512	MFM	800	.img
	ensoniq.1600	2	80	300	500	20	512	MFM-HD	1600	.img
	gem.1600	2	80	300	500	20	512	MFM-HD	1600	.img
	sci.prophet	2	80	300	250	5	1024	MFM	800	.img
ZX Spectrum	zx.trdos.640	2	80	300	250	16	256	MFM	640	.mgt, .dsk
	zx.quorum.800	2	80	300	250	5	1024	MFM	800	.mgt, .dsk
MicroWare OS-9	mm1.os9.80ds.hd32spt	2	80	300	500	32	256	MFM-HD	1280	.img
	mm1.os9.80ds.hd36spt	2	80	300	500	36	256	MFM-HD	1440	.img
5.25-inch disks	profile	sides	cyls	RPM	kbit/s	sct/trk	byt/sct	encoding	size (KB)	suffix
Acorn Atom	acorn.dfs.ss	1	40	300	125	10	256	FM	100	.ssd
	acorn.dfs.ds	2	40	300	125	10	256	FM	200	.dsd
BBC	acorn.adfs.160	1	40	300	250	16	256	MFM	160	.ads
	acorn.adfs.320	1	80	300	250	16	256	MFM	320	.adm
	acorn.adfs.640	2	80	300	250	16	256	MFM	640	.adl
Atari 800	atari.90	1	40	288	125	18	128	FM	90	.img
Vic20/C64	commodore.1541	1	35	300	VAR	21-17	256	GCR	170	.d64
/C128	commodore.1571	2	35	300	VAR	21-17	256	GCR	340	.d71
Dragon 32/64	dragon.40ss	1	40	300	250	18	256	MFM	180	.img
	dragon.40ds	2	40	300	250	18	256	MFM	360	.img
	dragon.80ss	1	80	300	250	18	256	MFM	360	.img
	dragon.80ds	2	80	300	250	18	256	MFM	720	.img
IBM PC	ibm.160	1	40	300	250	8	512	MFM	160	.img, .ima
	ibm.180	1	40	300	250	9	512	MFM	180	.img, .ima
	ibm.320	2	40	300	250	8	512	MFM	320	.img, .ima
	ibm.360	2	40	300	250	9	512	MFM	360	.img, .ima
	ibm.1200	2	80	360	500	15	512	MFM-HD	1200	.img
MSX	msx.1d	1	40	300	250	9	512	MFM	180	.dsk
	msx.2d	2	40	300	250	9	512	MFM	360	.dsk
Nec PC88/PC98	pc98.2d	2	40	300	250	8	512	MFM	320	.hdm, .xdf
	pc98.2dd	2	77	360	250	8	512	MFM	616	.hdm, .xdf
	pc98.n88basic.hd	2	77	360	500	26	256	MFM-HD	998	.hdm, .xdf
	pc98.2hd	2	77	360	500	8	1024	MFM-HD	1232	.hdm, .xd
CP/M - Osborne 1	occ1.sd	1	40	300	125	10	256	FM	100	.img
	occ1.dd	1	40	300	250	5	1024	MFM	200	.img
Olivetti M20	olivetti.m20	2	35	300	250	16	256	MFM	278	.img
Tandy CoCo	coco.decb	1	35	300	250	18	256	MFM	157.5	.img
	coco.decb.40t	1	40	300	250	18	256	MFM	180	.img
	coco.os9.40ss	1	40	300	250	18	256	MFM	180	.img
	coco.os9.40ds	2	40	300	250	18	256	MFM	360	.img
	coco.os9.80ss	1	80	300	250	18	256	MFM	360	.img
	coco.os9.80ds	2	80	300	250	18	256	MFM	720	.img
TSC Flex	tsc.flex.ssdd	1	80	300	250	18	256	MFM	358	.img
	tsc.flex.dsdd	2	80	300	250	18	256	MFM	715	.img
8-inch disks	profile	sides	cyls	RPM	kbit/s	sct/trk	byt/sct	encoding	size (KB)	suffix
DEC RX	dec.rx01	1	77	360	250	26	128	FM	250.25	.img
(PDP-11/VAX)	dec.rx02	1	77	360	250	26	256	M2FM	500,5	.img
3-inch disks	profile	sides	cyls	RPM	kbit/s	sct/trk	byt/sct	encoding	size (KB)	suffix
Sega SC-3000	sega.sf7000	1	40	300	250	16	256	MFM	160	.sf7

The gw command does an honest job at supporting dozens of disk formats and image formats, but it doesn’t directly support all of them yet. This list keeps evolving. To know all the possible disk format profiles and disk image suffixes supported by your latest version of the gw command, just type:

gw read --help

Don't despair if you don’t see the profile of your floppy disk in the list. Predefined profiles are just shortcuts for working with specific formats. Right now, Greaseweazle offers other ways of saving and recreating all your floppy disks.

Level #2: Troubleshooting common errors

Here are the few common errors many beginners encounter and how you can resolve them:

Error “No Index”:

Symptom: The gw command has asked the drive to start its motor, but the drive never confirms that the floppy disk is actually spinning.

Probable cause: you have not specified the correct drive unit in the command line.

Solution: add "--drive=" to the command line and specify the correct ID. This could be:

--drive=a when you are using the PC drive at the end of the cable, on a cable with a twist.

--drive=b: when you are using the PC drive in the middle of the cable, on a cable with a twist.

--drive=0, or 1, or 2: on a flat cable (without any twist), when you are using the drive whose plastic jumpers (on the rear) configure the DS0, DS1 or DS2 unit respectively.

Special case: when you connect a PC drive (without plastic jumpers) to a flat cable, it always has unit DS1 (--drive=1).

Other possible causes: there is no power supply for the drive, you plug the ribbon cable upside-down, you forgot to insert a floppy disk into the drive.

Error “Track 0 not found”:

Symptom: the drive has been selected, but something is missing to tell that it has managed to position its head on track 0.

Probable cause: the drive doesn't have enough power to operate normally.

Solution: the power source needs to be changed. Either:

- if the drive is powered by the Greaseweazle board, plug the Greaseweazle board into another USB port.

- if the drive is powered by an external power source (power supply, self-powered USB hub, etc.), unplug the other devices connected to this power source.

- If the error persists, supply your drive with a more efficient power source.

Other possible causes: When several drives are attached on the ribbon cable, this error can also be caused by a wrong drive selection. Check the solution given for the “No Index” error in this case.

Errors “Flux Overflow” or “Flux Underflow”

Symptom: The data from the Greaseweazle board is not arriving at the right speed.

Probable cause: there is interference in the USB connection.

Solution: plug the Greaseweazle card into another USB port on your computer. If no USB port solves the problem, change your USB cable.

Errors: “Verify Failure”, “Failed to verify Track”

Symptom: When writing, something is preventing a certain area on the surface of your diskette from storing information correctly.

Probable cause: there is mould on the surface of your floppy disk.

Solution: gently clean the surface of your floppy disk with a microfibre cloth soaked in 70% Isopropyl alcohol. Unfortunately, the result is not guaranteed. If the errors keep recurring on other diskettes, clean the heads of your drive too.

For more troubleshooting, see this page.

Level #3: more disk formats with meta-profiles and meta-disk images

The gw command also provides 'metaprofiles' which, without necessarily referring to a particular type of formatting, capture all the sectors present on a floppy disk, whatever their number, size, numbering scheme or formatting bytes used. These metaprofiles are called:

- ibm.scan: all FM or MFM encoded floppy disks,

- raw.125: all single-density floppy disks,

- raw.250: all double-density floppy disks,

- raw.500: all high-density floppy disks.

They are accompanied by 'meta-images' which store not only the contents of the sectors, but also their number, size, etc. These 'meta-images' are:

- .edsk: this is the disk image format favoured by British Z80 machine emulators (Sinclair, Amstrad, Sam Coupé and all MGT floppy disk systems).

- .imd: a format invented in the MS-DOS era to allow a PC to save any type of floppy disk readable by its floppy disk controller as an image.

To use these meta-profiles and meta-images, you must manually specify the geometry of the floppy disk using the "--tracks=" option, followed by various arguments:

- c=: the range of cylinders to be read. This means the tracks accessible by the drive head, the first being numbered "0" and the last being the 39th or 79th depending on the 40 or 80 track formats. For example: "c=0-79".

- h=: the drive heads to be used, to indicate whether only one side is to be accessed ("h=0"), both sides of the diskette ("h=0-1"), or only the second side of the diskette ("h=1").

See here for a more in-depth explanation of how to use the --tracks option.

For example, to backup a 180 KB Amstrad CPC floppy disk, which has a single side with 40 tracks, to a "MyCPCdisk.edsk" image, using a drive with ID "0" (Amstrad floppy disks are 3-inch, 3-inch drives being of the Shugart type, they necessarily have ID "0", "1" or "2"), you would do :

gw read --format=ibm.scan MyCPCdisk.edsk --drive=0 --tracks=c=0-39:h=0

Writing a floppy disk from a meta-image is much simpler. All the geometry of the floppy disk being already indicated in the meta-image, you indicate neither the profile nor the quantity of tracks in the command line:

gw write MyCPCdisk.edsk --drive=0

Note that emulators that use .edsk images prefer the ".dsk" suffix. When reading a floppy disk with the gw command, you should always use the ".edsk" suffix to avoid confusion with plain ".dsk" images. But remember to rename your ".edsk" images to ".dsk" before using them with an emulator.

However, you can use such an image with the suffix ".dsk" to write a floppy disk; the command will detect its type automatically when reading it.

Level #4: manage 5.25-inch 48-TPI disks with your 5.25-inch 96-TPI drive

With 5.25-inch disks, there are two sizes for the floppy drive’s head: 48 TPI and 96 TPI.

When they are written by a 48 TPI floppy drive, floppy disks contain around 40 'thick' tracks (from 35 to 42, depending on the format).

When they are written by a 96 TPI floppy drive, they contain around 80 'thin' tracks (sometimes up to 82).

The good news is that you can absolutely read a 48 TPI floppy disk from a 96 TPI floppy drive when you ask your drive to read one track every two tracks. You tell this in the command line with the "--tracks=" option and its "step=2" argument applied to the interval of tracks you want to read.

For instance, let’s say you want to read a 2-side, 40-track Dragon 32/64 floppy disk, using a 5.25-inch Teac FD-55GFR floppy drive, which is a 96-TPI drive. You would do:

gw read --format= dragon.40ds MyDragonDisk.img --tracks=c=0-39:step=2

Side note: a 48 TPI floppy disk is in all cases also a “double density” disk (DD), while a 96 TPI drive is most often also a “high density” floppy drive (HD). This has nothing to do with track thickness, but is related to the amount of current the floppy drive head uses to read/write a floppy disk made of iron oxide (double density) or cobalt (high density). To force an HD floppy drive to adapt to a DD floppy disk, it may be useful to add the --dd L option to the command line.

Writing a 48 TPI floppy disk with a 96 TPI floppy drive is a bit more complicated than just replace “read” by “write”. This floppy drive writes tracks that are twice too thin compared to real 48 TPI tracks. If your floppy disk has been previously written with a 48 TPI floppy drive, then half of the old “thick” tracks will remain in between the new "thin" tracks you are writing. At the end, the 48 TPI drive in your old computer will read at the same time your newly written thin track + half of an old thick track. It will fail.

A solution - not guaranteed! - would be to completely erase your floppy disk before writing on it, by passing a magnet over its entire surface. This will leave no trace of the old thick tracks between the new thin tracks.

But the most reliable solution is to only write 48 floppy disks with 48 TPI floppy drives.

Level #5: work at the magnetic flux level to read/write any disk (even copy-protected)

In the examples above, the gw command automates a complex process of backing up the useful contents of an uncopy-protected floppy disk to a disk image compatible with your emulator. Or it does the opposite: it automates the writing of a physical floppy disk from a disk image that contains the data useful to an emulator. But that's not necessarily what you want to do.

The Greaseweazle solution also allows you to archive the complete magnetic flux on the surface of your floppy disk. This is useful when you want to keep an archive of an original floppy disk, possibly copy-protected, so that you can recreate a strictly identical copy later. It is also useful for capturing a floppy disk whose formatting is not directly supported by the gw command.

It works like a photocopy of the surface of your disk. It works with any disk format, you don't even need to tell which format your disk is, just put the right suffix at the end of your archive name. The supported archive formats are:

• .scp : A long detailed digitized flux in very high definition, better for archiving purposes of special disk formats. But expect dozens of MegaBytes for the size of the archive of a simple double density disk. This archive format was invented for the older archiving solution SuperCard Pro.

• .ctr : The same as above. This archive format was invented for the older archiving solution Kryoflux.

• .raw : The same as above, but with one separate file per track. This archive format was invented for the older archiving solution Kryoflux.

• .hfe : a digitized flux at the exact resolution of the bitcells, the smallest bits of useful data on a floppy disk. Expect around twice the size of your original disk for the archive (2 MB for the archive of an Amiga disk, for instance). This archive format was invented for the HxC floppy drive emulator.

However, when you work at the flux level, you need to manually tell gw the speed of the recording it is supposed to read. The speed of the recording is the rotation speed in RPM for .scp, .ctr and .raw archives, or a bitrate in kbit/s for .hfe archives. And, as before, you must also tell the number of tracks to read.

RPM (for .scp, .ctr and .raw archives): the Rotations Per Minute your disk was initially recorded with. Most of the drives spin at 300 RPM, except:

• the latest 5.25-inch and all the 8-inch drives, who spin at 360 RPM.

- the Atari 810 and 1050 drives, who spin at 288 RPM.

So, here's the scenario you might encounter: you want to archive an Acorn BBC floppy disk that was written on a 300 RPM drive with your last generation 5.25-inch 1200 KB drive, which runs at 360 RPM. The data will be read too quickly. Specifying the original RPM number, with the option “--adjust-speed”, will correct this problem.

Here are some examples:

• To archive an Atari 800XL 5.25-inch disk, that has one side formatted and 40 “thick” tracks (48 TPI), originally written at 288 RPM, into a “MyAtari800Disk.scp” file, using a 5.25-inch Teac FD-55GFR drive, that is a 96 TPI drive spinning at 360 RPM, you will do:

gw read MyAtari800Disk.scp --tracks="c=0-39:h=0:step=2" --adjust-speed=288rpm

- To archive an IBM PC-XT “360 KB” 5.25-inch disk, that has two sides and 40 “thick” tracks (48 TPI) originally written at 300 RPM, into a “MyIBMdisk.scp” file, using the same 96 TPI/360 RPM drive, you will do:

gw read MyIBMdisk.scp --tracks="c=0-39:step=2" --adjust-speed=300rpm

- To archive a MSX 3.5-inch disk, that has one side formatted, into a “MyMSXdisk.scp” file, using any 3.5-inch drive, disk and drive being both in 80 tracks and 300 RPM:

gw read MyMSXdisk.scp --tracks="c=0-79:h=0”

- To archive any Amiga disk, being double density (880 KB) or high density (1760 KB), being copy-protected or not, into a “MyAmigaDisk.scp” file, using any 3.5-inch drive:

gw read MyAmigaDisk.scp

Side note: When you do not specify a format, the gw command does not check that the flux it is reading is error-free. This is desirable for capturing protections that are based on malformed data. But there is a risk that you will also capture random errors. To avoid this pitfall, it is possible to combine format checking with saving the content in flux mode, using the --format and --raw options together, as follows:

gw read --format=amiga.amigados MyAmigaDisk.scp --raw

Bitrate (for .hfe archives only): for disks encoded in FM/MFM, there are four possible bitrates, depending on the 'density' of your floppy disk:

- 125 kbit/s for 'single density' floppy disks (aka SD: early computers)

- 250 kbit/s for 'double density' floppy disks (aka DD: most computers created during the 80’s)

- 500 kbit/s for "high density" floppy disks (aka HD: IBM PC-AT and every other computer launched after it)

- 1000 kbit/s for "Extra high density" floppy disks (aka ED, mainly latest IBM PS/2 and NeXT’s computers)
You specify this by adding “::bitrate=” right after the suffix of your .hfe archive name.

Here are some examples:

To archive an Atari ST 3.5-inch disk, that has two sides formatted at double density, into a “MyAtariSTdisk.hfe” file suitable for a HxC drive emulator, using any 3.5-inch drive:

gw read MyAtariSTdisk.hfe::bitrate=250

To archive an Amstrad CPC 3-inch disk, that has only one side formatted at double density and 40 tracks, into a “MyAmstradCPCdisk.hfe” suitable for a HxC drive emulator, using an original Amstrad 3-inch floppy drive that has unit ID 0 and that also reads/writes 40 ‘thick’ tracks:

gw read MyAmstradCPCdisk.hfe::bitrate=250 --tracks="c=0-39:h=0” --drive=0

The good news is all the speed and tracks information is stored into these archives. So, you don’t have to tell it again when you write the .scp or .hfe file back to the disk. For instance:

gw write MyAmstradCPCdisk.hfe
gw write MyMSXdisk.scp

Level #6: yes, you can read any disk, except (probably) “flippy” 5.25-inch disks

In most cases, Commodore, Apple and Atari 800 5.25-inch floppy disks that were recorded on both sides, by physically flipping the disk, will not be supported.

The problem is not in the Greaseweazle solution, but in the 5.25-inch floppy drive you use, that is physically incompatible with “flippy disks”. It relies on the “index hole” to evaluate the speed of the disk before any read/write operation. But when you flip a disk upside down, the index hole is no more in front of the optical probe.

That said, it has been reported that some rare 5.25-inch drives support reading floppy disks without using index hole, thanks to a special configuration of their plastic jumpers. On the Panasonic JU-475-4, for instance, you achieve this mode of operation by removing the jumper from the GX position and move it on the EX position.

If your drive has this kind of feature, then you must manually tell the gw command what is the rotation speed (in RPM) of your drive with the option “--fake-index”. For instance, if you want to read the flipped side of a C64 floppy disk with a JU-475-4, which is a 96 TPI and 360 RPM drive, you would insert it upside down into your drive and type:

gw read --format=commodore.1541 MyC64sideB.d64 --tracks=”c=0-35:h=0:step=2” --fake-index=360rpm

Note that --fake-index is related here to the rotation speed of the drive you are using. It is not the rotation speed used by the original computer to write the floppy disk you are reading. For instance, let’s take one complex example: you want to dump the flipped side of a 35-track Apple II floppy disk, written in 300 RPM and 48 TPI, into a “MyApple2SideB.scp” archive, using a 96 TPI and 360 RPM drive. You would insert the disk upside down into your drive and type:

gw read MyApple2SideB.scp --tracks=”c=0-35:h=0:step=2” --adjust-speed=300rpm --fake-index=360rpm

For more information about flippy disks, see this page.

Level #7: Restore floppy disks from even more image disks

Beyond .edsk, .imd, .scp, .ctr, .raw and .hfe, other self-descriptive disk images exist. The gw command cannot create them for some reason (legal, lack of documentation, time missing…), but it can read them to write their content back to a physical floppy disk. The supported formats are:

.a2r : archive of flux, dedicated to Apple II floppy disks,

.d88, .dcp, .dim, .fdi : meta-image dedicated to Japanese Nec 88xx/98xx and X68000 floppy disks,

.tdo : similar to .imd.

.ipf : similar to .hfe + metadata. Please note that support of .ipf disk images is optional. To install its library on your system, read this page.

Then, to generate an Amiga physical floppy disk from a MyAmigaGame.ipf file, for instance, you would do:

gw write MyAmigaGame.ipf

Level #8: complete your Greaseweazle experience with other tools

You still can’t find in the gw command the support for the disk images of your choice? Then use .scp, .hfe; .edsk or .imd images with Greaseweazle and install third-party tools that will make the bridge between theses disk images and other ones. Here are some extra tools, compatible with Windows, macOS and Linux, that you could use to expand your Greaseweazle experience:

Disk Utilities: helpful to convert a .scp or an old .dfi flux archive of a protected floppy disk into an .ipf image easier to write with a Greaseweazle or to use with an emulator.

HxC Floppy Emulator: to convert many exotic disk images (Apple II .po or .do, Atari ST .stx; Atari 800 .atr, NorthStar .nsi, Dragon 32/64 .vdk, Thomson MO/TO .fd, TRS-80 .jv3 or .jv1, and a dozen of audio keyboard proprietary images, among others) to .hfe or .scp archives writable with the gw command.

It can also convert .scp or .hfe archives created with gw command to .po, .do, .stx, .nsi, .vdk, .fd, or .jv3 images usable with emulators.

This software exists in command line and GUI versions. The GUI version also offers a graphic disk analyser to visually detect errors on flux archives created with Greaseweazle.

SamDisk: to convert even more exotic disk images (Amstrad .dsc and .cfi, C64 CMD FD-2000/4000 .d2m or .d4m, HP LIF .lif, Jupiter Ace Sam Coupé .sad or .sbt, Sega System 24 .s24, TRS-80 .dmk, ZX Spectrum .mbd, .opd,.scl or .udi, among others) to .edsk meta-images writable with the gw command.

It can also help to convert .edsk images created with the gw command to .d2m, .d4m, .lif, .sad, .mbd, and .opd images compatible with some emulators.

a8rawconv (FTP link): to convert .scp archives of Atari 800 disks created by the gw command to .atr, .atx, or .xfd images compatibles with emulators. Or the opposite: to convert .atr, .atx and .xfd images into a .scp archive writable to floppy disk with the gw command.

Fluxengine: This is an alternative command to gw, which supports other floppy disk formats, like Apple II AppleDos or ProDos, Victor 9000, among others.

Level #9: create your own profile to support a specific disk format

All the profiles used with the --format option are described in the diskdefs.cfg configuration file that is installed with the gw command. If you feel that you are familiar with the characteristics of a certain floppy disk formatting which is not directly supported by any profile of the gw command, you can write its specifications as a new profile into a configuration file following the pattern in diskdefs.cfg.

Then, to read a floppy disk with a custom profile that you named, for instance, my.disk.format and that you saved in a configuration file named, for instance, MyFormats.cfg, you would type:

gw read --diskdefs=MyFormats.cfg --format=my.disk.format MyDisk.img