Mounting ADF's

[prowler]

Originally Posted by Arnie

I have used Diskspare in the past. As far as I can remember there are 2 different sizes of disk, 960kb and 984kb, depending on the version of diskpsare you use.

Originally Posted by prowler

I have only seen the 960K size with 12 sectors per track instead of 11 (hence DiskSpare). The only images I have seen in the 984K size turned out to be padded with 24K of zeroes at the end!

I'm just getting my head round all this again...

I've just worked out what the 984K DiskSpare disk images most likely are, and why all those I have seen (on the EAB File Server, IIRC) are padded with zeroes!

The mountlist muist have 82 tracks per side instead of 80! But those images are dumps of disks with only 80 tracks per side, so the last 24K of data are zeroed out!

[Arnie]

Yeah, weird. I've never come across any dumped disks with 984kb, the Superdisks I have are all 960kb.

Can you tell me why some of the early Superdisks (not diskspare) are 902kb disks but show as 836 in workbench?

[Toni Wilen]

Originally Posted by Arnie

Can you tell me why some of the early Superdisks (not diskspare) are 902kb disks but show as 836 in workbench?

OFS formatted?

[Arnie]

Yes they are but, why the 902kb file size. Shouldn't it be 836kb?

[Toni Wilen]

Perhaps you meant something else but OFS disk data block size is 488 bytes, 24 bytes is wasted (512 byte blocks) for OFS book keeping information. (OFS 880k adf does not have 880k free either)

[Arnie]

Originally Posted by Toni Wilen

Perhaps you meant something else but OFS disk data block size is 488 bytes, 24 bytes is wasted (512 byte blocks) for OFS book keeping information. (OFS 880k adf does not have 880k free either)

OK thanks

So irrespective of whether it's OFS or FFS formatted the files size is the same, 901120.

I have different size diskspare disks so I'm trying to find out what loads what.

901120 AmigaDOS FFS/OFS

923648 AmigaDOS FFS/OFS

983040 DiskSpare FFS/OFS (960kb)

1007218 DiskSpare FFS/OFS (984kb)

The only one which is puzzling me is 923648, it's an AmigaDOS 880kb disk but, larger than a standard ADF?

[prowler]

Originally Posted by Arnie

The only one which is puzzling me is 923648, it's an AmigaDOS 880kb disk but, larger than a standard ADF?

This 902K disk has 82 tracks per side, whereas the 880K disk has 80 tracks per side. Both disks have 11x512-byte sectors per track.

[mark_k]

Yes that one's a bit strange. Did anyone ever hack trackdisk.device to do 82 tracks? If Arnie could upload one of the 923648-byte image files, we could see whether it's an under-dumped DiskSpare disk or not. (Maybe whoever dumped it accidentally used a mount file with 11 sectors per track instead of 12???)

[prowler]

Originally Posted by mark_k

If Arnie could upload one of the 923648-byte image files, we could see whether it's an under-dumped DiskSpare disk or not. (Maybe whoever dumped it accidentally used a mount file with 11 sectors per track instead of 12???)

Is that a realistic possibility, even when using a device which supports both formats?

[Arnie]

@mark

Download the file AUI #2 from the eab fileserver

(commodore_amiga/collection/coverdisk/amiga user international)

@Prowler

Do I need 2 mountlists for diskspare, one for 960kb and one for 984kb or is there a way for the 984kb mountlist to mount 960kb & 984kb ADF's?

[prowler]

Originally Posted by Arnie

@Prowler

Do I need 2 mountlists for diskspare, one for 960kb and one for 984kb or is there a way for the 984kb mountlist to mount 960kb & 984kb ADF's?

I suspect that you do, but I really don't know because I haven't tried it.

If you were to use a mountlist with 82 tracks per side to mount a 960K DiskSpare-formatted floppy disk and tried to dump it, then the last two cylinders of the image would be zeroed out, because they would appear as bad tracks, but it you were to mount a 960K ADF image with the same mountlist, then I suspect you would get an error due to geometry mismatch, but even if you succeeded in mounting it, you would be risking filesystem errors and/or overwritten files if you tried to writing to the image.

And if you were to use a mountlist with 80 tracks per side to mount a 984K DiskSpare-formatted floppy disk and tried to dump it, then the last two cylinders of the image would be ignored, and you'd get only a 960K ADF image. Mounting a 984K ADF image with this mountlist would leave you unable to access the last two cylinders of the image.

[Arnie]

2 mountlists it is then.

I have also managed to mount ms-dos (PC0) and DMS images. So they will be in the next release.

I'm running out of unit numbers so I may have to cut back on trackdisk and diskspare drives. Or find a way to share unit numbers. I need something like multifilesystem for virtual drives.

[prowler]

Originally Posted by Arnie

I have also managed to mount ms-dos (PC0) and DMS images. So they will be in the next release.

This is turning out to be a very useful tool for use in Amiga emulation and real machines.

Originally Posted by Arnie

I'm running out of unit numbers so I may have to cut back on trackdisk and diskspare drives. Or find a way to share unit numbers. I need something like multifilesystem for virtual drives.

You know, you don't have to stick to DFn:, DSn:, etc. You can use another alias if it means cutting back on those drives. You can even use three letters to make them more descriptive, like for Macintosh disks with CrossMac, i.e. MACn:.

I notice in the release notes for diskimage.device that the author found FMS often crashed when mounting an "fmsdisk.device" image. I used the later of the two available versions when I used it an an alternative to a real floppy drive and it was very reliable. However, the best feature of diskimage.device is the way it allows you to swap virtual floppies.

[mark_k]

Originally Posted by Arnie

Download the file AUI #2 from the eab fileserver

(commodore_amiga/collection/coverdisk/amiga user international)

I took a look at that file. It's a standard 901120-byte trackdisk-type image with two tracks' worth of extra data at the end.

The extra data is just "garbage" and should be deleted. It is actually the last sector (512 bytes) in the 901120-byte image, repeated 44 times. Perhaps whoever dumped that disk used some program which attempted to dump 82 tracks, but when it couldn't read past the 80th track, the program wrote the last-correctly-read sector data to the image file over and over.

[Arnie]

Due to the rather inclement weather, I have had some spare time to work on MountADF.

I have added support for ms-dos 720kb, DMS disks & ISO's

ADZ's, Diskspare 960kb and 984kb also work.

[prowler]

Thanks, Arnie!

This is turning out to be quite some tool!

Hehe, it's because of the ghastly weather here that I haven't had much spare time lately. We're virtually cut off here as a result of the snowfall today! My new shovel's come in quite handy, though.

[Turran]

Yay Weather. Thanks =)

[Arnie]

Would there be any need/interest/purpose in being able to boot from Adf disks (AmigaDos)?

[prowler]

Originally Posted by Arnie

Would there be any need/interest/purpose in being able to boot from Adf disks (AmigaDos)?

Not for me personally, but I'm sure I have seen interest in such a utility being expressed in these forums by other users.

[amigasith]

Hi there,

how is this solution different from this one here: http://aminet.net/package/disk/misc/diskimage.m68k-aos ? I tried it before I found this thread and it works quite nicely (I don't use the GUI, however).

EDIT: Forgot to mention that diskimage.m68k-aos also supports ADFs...