bootable hard disk image

[degan24]

I have a MAC SE/30 that I am trying to resurrect so that I can read in disks that I have, and ultimately use them in the emulator.

Should I be able to take one of the images that works in the emulator, ie; hfs10M.DSK, and copy it to a scsi disk using dd

dd if=hfs10M.DSK of=/dev/sdd (from Linux or Cygwin)

and expect my SE to boot from the imaged SCSI?

I was hoping to 'dd' a bootable image to the scsi to boot the SE, copy all of my disks onto the scsi disk, then dd the scsi back to a memory image to use with the emulator.

When I try to boot the SE with the imaged scsi, I see the disk being selected at regular intervals, but it just won't boot. I have a floppy disk that boots "Copy II Mac / Mac Tools", but the scsi disk doesn't show up. So I don't know if the scsi interface is broken, or the image on the disk is not valid. I have tried several scsi disks.


Doug Egan

[gryphel]

I know that copying a correctly sized image to a floppy drive this way will work. I'm not so familiar with doing this on hard drives. I think it would work to copy an image to one of the partitions of the hard drive, not the entire hard drive. (Depending on operating system, perhaps something like "/dev/sdd3", instead of "/dev/sdd".) I think a hard drive for an early Mac would normally have a partition map and a device driver on the disk. Without those the Mac probably doesn't know what to do with it.

So the safer way to experiment could be to use "dd" to copy a partition from the hard drive, make sure Mini vMac can mount the image, modify it as desired in Mini vMac, and then write the partition back to the drive. (And I expect you first need to reformat the hard drives you've already experimented with, using the Mac so as to make sure to get the correct device driver on it.)

[24bit]

Hi,
as far as I can recall the SE30 already came with the so called Superdrive floppy drive. So you should be able to boot from a high density disk with e.g. Mac OS 6.08.
You should then be able to format your SCSI harddisk if it is accepted by the Mac OS.
gryphel is quite right, without correct device driver and hfs catalog B-tree there is hardly a chance to make it.
If you wish, I could send you a floppy via snail mail, with a working OS and a SCSI setup utility that should format your drive.
Another chance might be the old Apple CD300 ROM drive, that could be connected to the external SCSI bus.
You should then be able to boot from CD. Maybe you can still find one of those, any other external SCSI CD device should be fine too.
Yamaha made some, for burning compact disks with the Mac.

If nothing should work, I would be willing to read out your old disks and copy the contents to some .img file for you.
Best wishes!

[degan24]

First, my machine is not an official 'SE/30'. It is just an SE which originally shipped with 2 - 800K drives, one of those is still installed. I got it from a local elementary school a few years ago and this is the first time I turned it on. It is definitely a homegrown SE. It will boot my 'Copy II Mac' tools disk. I went through the whole early MAC craze; Mac 128, turned it into a MAC 512, and then got a Mac SE with external hard drive. All I have from that part of my life is just some data disks and no system disks. That's why this emulator is so useful.

As far as partition tables, wouldn't the disk image that I use in minivmac have a partition table in it? The disk image is a 10Meg file, so it is definitely not a floppy image. I would think the bootroms used by the minivmac would read the disk image as a hard disk, analyze the partition table and go from there looking for the System folder.

I made this emulator image by first running dd to create an empty 10meg file. Then when the emulator was running with a good image, I dropped the empty image onto the desktop. The OS then asked me to Initialize the disk. Once the disk was initialized, I copied the contents of the booted image to the new image. Now the new image boots as well.

Do MAC partition tables look like those created with fdisk? 4 partition tables in the first sector? I don't think so.

Thanks,
Doug

[degan24]

Can anyone answer if the disk driver in minivmac treats all disk images the same; 400K or 800K or 20Meg, all have the same sector 0 indicating a start sector, end sector, size, but no true partition tables?

A great enhancement would be to allow a scsi drive to be hooked up to a pc or linux box, and have the emulator access that device via a raw device node ie; /dev/sda0 or \\.\PHYSICALDRIVE1

[IIsi 50MHz]

Basic'ly, Mini vMac does not emulate true hard discs. I second 24bit's suggestions for reaching your data.

Mini vMac does not emulate the floppy drive hardware but instead patches the ROM with a replacement disk driver, which can mount up to 6 “disk image” files.

Besides 400K or 800K, the replacement disk driver of Mini vMac will also work with disk images of any other size less than 2G. It will pretend to have something more like a hard disk, though not exactly. This is not too authentic, but it is very useful. Mini vMac defines its own icon for these disks (with a ‘v’), which can be seen in the Finder on the emulated computer.

For slightly more detail on how Mini vMac handles disc images, see http://minivmac.sourceforge.net/doc/har ... ppy_drives


(( 24bit: Someday I'd like to ask you to read the data off an old SCSI drive for me, in exchange for the drive itself perhaps. Either that, or I'll have to get courageous with a soldering iron and replace all the electrolytic capacitors on my IIsi zero-megahertz! ))

[Cat_7]

Hi,

The older versions of Basilisk for Windows (up to build 143) can use a scsi adapter and HFS disks connected to it. It would allow you to run system 7.5 (or perhaps lower, I don't know exactly which Mac OS versions the older Basilisk supports).
Newer SheepShaver/Basilisk builds can also boot from a real HFS partition in Linux.

Best,
Cat_7

[gryphel]

As far as partition tables, wouldn't the disk image that I use in minivmac have a partition table in it?

No. Mini vMac disk images are more like giant floppies in that respect. They have the same format as one partition of a hard drive and not an entire hard drive. (Actually many formats, such as MFS, HFS, and FAT.)

Can anyone answer if the disk driver in minivmac treats all disk images the same; 400K or 800K or 20Meg, all have the same sector 0 indicating a start sector, end sector, size, but no true partition tables?

Mini vMac does treat 400K and 800K disks somewhat differently than other sizes, but the differences don't matter for most purposes.

There is no partition table, and actually there is no such sector 0 either. For MFS and HFS disks, the first two sectors can either be blank or contain information used for booting. The exact size of the volume doesn't seem to be recorded anywhere.

I would think the bootroms used by the minivmac would read the disk image as a hard disk, analyze the partition table and go from there looking for the System folder.

The images are mounted by the replacement floppy disk driver, and not by the SCSI code in the ROM.

As Cat_7 suggests, some other emulators support SCSI emulation. That may allow you to reformat your hard drives, if you don't have software on floppies that can reformat it on your SE/30. After that it would just be a matter of preference which emulator to use. Or, that is, direct access to SCSI hardware would be convenient, but on the other hand, well, it wouldn't be appropriate for me to comment.

Another alternative is to use an emulator to create a bootable floppy with software to format a hard disk, if you have a 1.4M floppy drive for your modern computer. Or you could accept 24bit's offer to mail you such a floppy.

[24bit]

Hello degan24,
OK, I see your point. Things will become a little tricky with only one 800k drive, but not impossible.
Apple released OS 6.08 for free a long time ago and I am sure there were 800k disk images available
those days. Can you find someone at your location with an old Mac who would diskcopy the images to real floppys?
You will need four 2DD floppys, maybe hard to find these days.
Surely you are aware of the fact that HD_Setup would only treat real Apple HD's in the past.
There is a patch for HD_Setup7.3.5, but I am unsure wether you can use that one with 6.
So you will best give it a try with an old original 700MB disk or such.

Good luck to you!

EDIT:
I just found, that I still have the original multilanguage System7 2DD floppys.
I hope, that is still possible to use them, as I haven't tried them for decades.
If you would like to have those, I would donate them to you.

EDIT2:
I created a 800k floppy with OS6 and AppleSC setup on it.
Both version 2 and 7 run in MiniVmac. The floppy is ready to be sent.
So its up to you...