Emulating a Mac LC 475 from real data

[Ezzio]

Hi.

A cousin o'mine has been using a LC 475 for quite some time, before storing it in its original carton box for the past five years.

The computer had stored in its hard drive a wealth of data, which recently became pretty much important to retrieve.

To make a long story short, the LC 475 is dead and none in my area is able to repair it. One repair shop actually said it could, but the fee was something around 300 EUR ( for starters )...

As far as we know, the hard disk isn't damaged, it's just the power supply unit that blew off. The idea is to make an image out of the hard drive and emulate it on my cousin's PC or Mac via Basilisk-II or SheepShaver.

I have the ROM dumps of the machine, which I made via an EPROM programmer. Can you suggest me some tools on the PC to read the data off of the hard drive and convert it to HFV? Which is the best and faster way to do this?

Ultimately, if I recreate all the LC 475 specs in the emulator, will the emulated system run off the hook thinking it's running on top of the real thing?

Thanks.

Ezzio

 

[porter]

The computer had stored in its hard drive a wealth of data, which recently became pretty much important to retrieve.

1. Change the hard disk's SCSI id by adding a jumper.

2. Plug into an external disk chassis.

3. Plug that into a working classic macintosh.

4. Copy files to safe location.

 

[dav7]

Disclaimer: Never tried this random guess myself, I have no idea if it will work.

I don't know if BasiliskII is equivalent to an LC 475 in terms of emulation - it is if the 475 can't run Mac OS 8 or later, afaik:

1. Find a PC with SCSI support on the mobo (these instructions only apply if said PC runs Linux).

2 Use BasiliskII's SCSI tab to map one of the emulated SCSI IDs to the real SCSI disk. The SCSI disk will be of the form /dev/sdN, where N is a number you'll need to figure out.

3. If you DO NOT want to use BasiliskII's "Unix root" feature:

3a. Create a disk image on the PC's HDD the size of the Mac's HDD and import it into BasiliskII.

4. If you DO want to use said "Unix root" feature:

4a. Ensure "Unix root" is filled in with a directory name of some sort under the Volumes tab.

5. If you can boot off the SCSI HDD do so, eitherwise boot a compatible installer CD or floppy to get the emulator running.

6. If you DO NOT want to use the "Unix root" feature:

6a. Initialize the virtual disk image.

6b. Copy everything across from the real hard disk onto the virtual disk image.

7. If you DO want to use the "Unix root" feature:

7a. Locate the disk named "Unix". Browse as little as possible because each directory you visit will be littered with .rsrc and .finf hidden directories as a way of preserving Mac OS resource forks and file information stored natively in the HFS file system.

-dav7

 

[Bunsen]

What's your location? In most places, the cheapest and simplest solution will be to do as porter suggests and find another SCSI equipped older Macintosh to do the transfer to another, safer, location. Even the actual 475 power supply should be readily available from someone here, or on ebay.

In terms of emulators, and exploring Mac disks from a Windows machine, check out the free and paid solutions from http://emulators.com/

You can read Mac disks from Windows/DOS machines with their free Gemulator Explorer. You will need a SCSI equipped PC or SCSI card, with the necessary connectors/converters to mount the 50 pin, low-density internal SCSI connector on the 475's hard disk.

http://emulators.com/download.htm#UTILITIES

This free release is limited to copying a single file at a time from the Mac or Atari disk to your PC's disk.

I assume there is a paid version.

Once the disk mounts, you should be able to read and write it with their SoftMac or Fusion emulators.

http://emulators.com/download.htm#MACINTOSH

 

[register]

If no working unit is available, consider to double-check for yourself if the battery used to buffer the clock chip and PRAM is in proper condition. I have not ever seen any broken LC power supply or mainboard, but even Apple computer sellers swapping the whole 475 mainboards instead of the battery. The 475 sometimes is misdiagnosed as dead because of a discharged lithium cell. This original 3 Volt (3,6 Volt) lithium battery is expensive, but a pair of two cheap 1,5 Volt alkaline cells in series will do, as well (batteries of different sizes can be used using an also cheap clip holder connected by wire to the original holder; just mind the polarity).

 

[Ezzio]

My cousin is not interested in repairing his old computer. Actually, I guess he will store it back in the box for posterity or give it to me.

At the moment, he is more concerned about the data. I was wondering if it's possible to read the RAW image with a tool such as DriveImage and then convert such RAW data to HFV for Emulation purposes. Any of you has a previous experience in doing this with DriveImage or, say, DFSee or any other PC Tools?

When the Mac was put out, the system was perfectly up and running. Doing an image of the WHOLE drive maybe I would be able to perfectly emulate the machine, and it's installed operating system, within a Basilisk-II / SheepShaver environment. What do you think?

 

[Morrick]

I think that, currently, you should focus on the hardware side of the issue, more than on which tool(s) might be able to read the disk. You need to find a way to make an old Mac-formatted internal SCSI drive work to be able to access its data. If you haven't got a PC that can support that kind of SCSI drive, if you haven't got another vintage Macintosh that could access that drive (either internally or externally via a SCSI enclosure properly terminated), then probably trying to fix the LC475 itself is the easiest path.

On that matter, I tend to agree with register -- if the 475 was working perfectly when it was put away, it seems unlikely that the power supply is at fault; the battery, drained out, might actually be the prime suspect. But then again, in almost 20 years of Mac experience, I've seen things which are closer to Black Magick than Computer Science

Cheers

Rick

 

[porter]

Don't forget to try powering up, then quickly off/on the power switch to kick the machine.

 

[Bunsen]

To clarify: some of the older Macs will refuse to start up when the motherboard battery is dead, and the LC475 is one of them.

The method porter describes gets around that fault. Leave it powered up for a minute or so, then very quickly off and on again. This will get enough charge into the machine for it to remember how to boot, after which it will operate as per normal until it is next powered down. This will allow you to recover the data.

Recovering the machine is especially worthwhile if there is an Ethernet card in it, as you will then have several relatively easy options to back up the data.

You will have much more success using an emulator, or a proper Mac HFS/HFS+ disk format utility for Win, than trying to recover and decipher the RAW data IMHO. The tools I have already pointed you to for example - although I must admit I wasn't expecting the free version of Gemulator Explorer to be so limited.

There is also a Win utility called MacDrive or MacDisk, which has a free 30-day trial, and no file size or number limitations AFAICR

Is the problem that you have no SCSI card on the PC end?

If you don't, no amount of software magic or wheel reinvention will help you read that disk on the PC. SCSI and IDE/ATA/SATA are completely different at the hardware level. They don't even have the same number of pins. If you try to somehow plug that drive into an IDE/ATA or SATA bus, you can expect to smell the tangy odor of burning components and data real soon.

Same goes for the parallel port - which does have the same physical format as some kinds of SCSI connector, leading to the not-infrequent destruction of both motherboards and drives.

Long story short: if you wanna read that drive on a PC, you need SCSI.

 

[Ezzio]

Hi Bunsen. Thanks for your reply.

I am accustomed to SCSI as I have a sh*tload of IBM PS/2 machines hanging around. Of course I have a PCI SCSI controller, from the days when the best CD burners around were SCSI. So I know what is SCSI and what is not [8D]

There is a tool from the vMac suite that actually converts RAW data to HFV. It's called IMG2HFV. But then I guess HFVExplorer is going to be fine.

I don't know, I will experiment with the available tools and let you know.

ATM, repairing the Mac itself is still not an option, because I don't have the machine handy: the repair shop is closed and all we have is the HDD.