Mount a ZuluSCSI image in MiniVMac

[flimshaw]

Apologies if I missed an answer out there somewhere. I've got a Mac Classic happily booting from an external ZuluSCSI rp2040. I also have a Classic build of MiniVMac running on my machine. I would love to be able to use images from either one on the other.

I know miniVmac uses images closer to diskettes (ie just a raw HFS file system), and that Zulu needs some additional header info for a partition table. I'm curious, would it be possible to take a DSK image from MiniVMac and wrap it in the appropriate partition table / header information it needs to boot on a ZuluSCSI? And, conversely, what would be needed to boot an image from a zulu SD card in MiniVMac?


Thanks!

 

[Realitystorm]

You're right, ZuluSCSI uses drive images, MiniVMac uses volume images.

I describe the difference between volume images and drive images on my site, and which emulators work with them, and how to convert between the two https://www.savagetaylor.com/downloads/downloads-macintosh/

 

[flimshaw]

Thanks so much, I was about to add that link to this thread! the dd commands were exactly what I was looking for. Haven't had a chance to try on the real hardware yet, but some promising experiments in emulator land.

I was curious about one thing: for the dd command where you basically just skip the first 48k, is that specific to zip drives / 100MB? Or would that formula work for larger drive sizes as well? I tried appending a 128MB volume image to a 100MB drive image skipping the first 48k and it _seems_ to work, but I don't know enough about the header format to know if there are more specific settings in that header.

Thanks again.

 

[joshc]

A disk image is a disk image, just a file containing data. There isn't really such a thing as a 'volume image' and a 'drive image', rather than there are images with and without a boot partition. mini vMac doens't need a boot partition because it sees disk images and mounts them as floppies - the floppy driver is built into the ROM so the image doesn't need a boot partition.

Basilisk, and a real Mac, will need a boot partition as it's going to mount as a hard drive via the SCSI bus, not as a floppy via the SWIM/IWM.

I may have gotten a few terms wrong here and there - but that's my basic understanding of this, and hopefully explains it in a way that is logical.

 

[nsputnik]

You're right, ZuluSCSI uses drive images, MiniVMac uses volume images.

I describe the difference between volume images and drive images on my site, and which emulators work with them, and how to convert between the two https://www.savagetaylor.com/downloads/downloads-macintosh/

I was looking to mount an image in both PiSCSI and Mini vMac. I found a quicker solution, Jean-Michel Durand's Disk Jockey app for both MacOS and Windows. It converts between Mini vMac .dsk to PiSCSI (Zulu and Blue as well, from what I understand) .hda and can convert that same .hda PiSCSI mountable back to a to .img which back to a Mini vMac mountable image (which you can even rename .dsk to keep it consistent and it will still mount in Mini vMac). https://diskjockey.onegeekarmy.eu/