SCSI ZIp Drive

[nahuelmarisi]

A few questions about the zip drive on an old compact mac:

Is it possible to hook up a 250mb scsi zip drive on to a mac Se/30?

Does any SCSI 100mb zip drive work with the Se/30?

Thanks

 

[LCGuy]

1. Yes, but you must have System 7. The Zip 250, unlike the 100, doesn't support System 6

2. Yes.

 

[Charlieman]

1The Zip 250, unlike the 100, doesn't support System 6

In what way do you mean that the Zip 250 does not work with System 6?

 

[nahuelmarisi]

Well I'm interested in it working with system 6 if possible. DOes the 250 work with it then?

And if so, where are the drivers? are the the same ones?

I'm interested in booting my plus from the zip drive if possible

 

[nahuelmarisi]

Well I'm interested in it working with system 6 if possible. DOes the 250 work with it then?

And if so, where are the drivers? are the the same ones?

I'm interested in booting my plus from the zip drive if possible

 

[tomlee59]

What LCguy is saying is that you cannot use a zip 250 with a system 6 machine. There are no sys6-compatible zip250 drivers (at least AFAIK). So your options are:

1) Use system 7 to allow use of a zip 250

2) Stay with system 6, but you'll then be limited to using zip100.

 

[Mac128]

The SCSI Zip 100 will boot my Dove MacSnap SCSI equipped Mac 512Ke from System .97 and Finder 1.0, once formatted with Driver 4.2 under 6.0.x

So it should boot the Mac SE all the way back to its original system software.

I love backward compatibility.

Could the Zip 250 be formatted under System 7, then used with System 6 in the same way I can use my Zip 100 disks under earlier systems?

Not to hijack this thread, but I would much prefer a ZIP drive inside a SCSI capable Mac rather than a hard drive to make it quieter and would require only minor modification to the SE case in order to insert the ZIP disks. In the case of the SE, my understanding is that analogue board is much sturdier than the Plus board in terms of heat resistance. I wonder if without the hard drive you could turn off the fan, or at least put it on a temperature controlled switch and the existing ventilation would be mostly adequate.

 

[aftermac]

Not to hijack this thread, but I would much prefer a ZIP drive inside a SCSI capable Mac rather than a hard drive to make it quieter and would require only minor modification to the SE case in order to insert the ZIP disks. In the case of the SE, my understanding is that analogue board is much sturdier than the Plus board in terms of heat resistance. I wonder if without the hard drive you could turn off the fan, or at least put it on a temperature controlled switch and the existing ventilation would be mostly adequate.

Not to foster your unintended hijacking, but that's not a half-bad idea.

 

[Charlieman]

System level drivers (INITs, extensions) are not required for hard disks or SCSI removeable drives (Bernoulli, Zip, Syquest). System level drivers provide additional functionality (on the fly ejection and re-insertion, for example), but a Mac should recognise any SCSI removeable drive if it is present on startup. If that fails, use SCSI Probe or a similar utility, and remove all Iomega INITs or extensions. Any decent third party disk formatter will operate on a Zip or similar removeable disk. Formatters put a "driver" on the disk but that driver is different from a system level INIT or extension.

Zips are more awkward to deal with. Iomega presumed that they knew more about SCSI disks than others, and the system level driver (INIT) looks at the disk to check whether it has been formatted in the approved fashion. Thus a Zip 250 cartridge will not work with the System 6 INIT because Zip 250s did not exist at the time. If you want to persevere with the System 6 Iomega software, open the INIT in a binary editor and change the references to "Zip 100" to "Zip 250". Or save time by removing the Iomega INIT and by using a third party formatter (System 6 and 7 compatible!) for your Zip disks alongside a SCSI control panel.

 

[nahuelmarisi]

Basicallly, if I understand correctly, I could get a zip 250 mb and use it as a zip 100 (ie using its driver) on system 6?

I don't mind if it just works as a zip 100 on system 6. I'm trying to decide what to get, if I zip 100 or a zip 250. I want it to be able to boot system 6, and well I can use it as a zip 250 in older macs.

I don't know if I'm making myself clear, but, basically using the zip 100 driver on system zip allows the zip 250 to work as if it was a zip 100 unit?

 

[tomlee59]

Charlieman's suggestion will allow you to mount a zip250 if you first boot from another disk. However, if you want to use a zip drive in lieu of a hard drive altogether, you will still need to solve the driver problem in a way that permits booting from that zip. I do not know how to make that work in system 6 with a zip250.

Btw, a zip250 is backwards compatible with a zip100, but writing a 100MB disk in a 250MB zip drive is *very* slow (about 3x-4x) because the narrower 250MB head has to make 3 passes (!) to erase and write 100MB tracks.

Since I have a pile of 100MB zip drives and disks, that's pretty much all I use. I do have a couple 250MB drives, but they get very little use because of that write speed issue with my large-ish collection of 100MB disks.

 

[Charlieman]

I have had a Mac Plus booting System 6 from both Zip 100 and 250 drives this evening. The trick is the preparation of the Zip cartridge. The procedure is similar for both types.

I used a Plus with a SCSI hard disk, placing the Zip drive as the last device on the external SCSI chain. The hard disk received a clean installation of System 6.0.8 (the AppleShare client was broken in the previous installation) with the Iomega INIT 4.2. For the Zip 250, I used an INIT that had been modified in the way described previously.

Cartridges that had previously been used in a variety of Macs were used for this exercise. It can be assumed that they had later drivers installed at the media level. Using the Anubis utility from CharisMac, cartridges were low level formatted (to completely remove the old media driver) and initialised. After quitting Anubis, the cartridges mounted on the desktop. I copied the System Folder from the hard disk to the Zip cartridge, shutdown and removed the hard disk from the SCSI chain.

I plugged in the Zip drive as the only device in the SCSI chain, and the Mac Plus simply booted. This even worked with a Zip 100 cartridge (previously formatted in a Zip 100 drive) in a Zip 250 drive. If you are booting from a Zip cartridge, the Iomega INIT does not need to be installed in the System Folder.

I ran out of time for further testing, so there are things worth trying. I don't know whether you actually need the INIT during the format process, and I'll try to repeat the tests without it. I used Anubis because I have had success using it with awkward SCSI media in the past. I turned off blind writes in the format (standard practice for a Plus or SE) but used the other defaults. Other formatting utilities should work, but you'll need to do your own homework. You don't need a hard disk to boot for the formatting, but it is quicker than using floppy disks. I used a late model Plus from 1989/1990 with third generation ROMs, so the procedure needs testing on earlier models.

 

[Mac128]

Charlieman, I'm not sure I followed ... you say you got the system to recognize an entire 250MB Zip disk with your modified INIT? Or just as a 100MB disk?

Also, I think you are doing what I have been describing on my site and above. In my case I boot up with 6.0.4 on a single 800K floppy with the Iomega 4.2 INIT, format a ZIP 100 disk and then I can install ANY system on it. The Mac will boot up from the ZIP 100 disk running any system from .97/Finder 1.0 up and DOES NOT NEED the Iomega 4.2 INIT in the system. This works on a 512Ke & Plus. As I speculated earlier I think the volume information is encoded on the disk and the Mac simply reads it and recognizes it, which may be why you can use 800K MFS disks with 64K ROMs. You can erase data on such disks, but not format new ones (well I haven't tried to format a new ZIP 100 while booted up from one, but I'll let you know). So I would assume the same to be true with the 250MB Zip, at least you should be able to use 4.2 INIT formated ZIP 100s in it and have them be recognized.

 

[tomlee59]

Charlieman -- this is great! Thanks for your hard work figuring all this out, and then also verifying the procedure. It's great to know that, if I ever want to migrate to a zip250 for my HD-less Plus, it can be done.

This info ought to be archived somewhere for easy access!

 

[Charlieman]

Charlieman, I'm not sure I followed ... you say you got the system to recognize an entire 250MB Zip disk with your modified INIT? Or just as a 100MB disk?

*Clarification*

The procedures above work for me with the following:

100MB cartridge in 100MB drive

250MB cartridge in 250MB drive

100MB cartridge in 250MB drive

Also, I think you are doing what I have been describing on my site and above.

Very similar. However, I am using pre-used cartridges that have various media drivers on them. The low level format is essential to remove any evidence of that driver. Otherwise we end up with the well reported problem with Pluses being unable to use or format cartridges that have been "updated" with a later media driver.

The Iomega INIT is *definitely* not required when booting from a Zip cartridge. The INIT manages cartridge ejection and remounts, which are not sensible features when you are using the Zip as your main hard disk! If you boot from a Zip cartridge with the Iomega INIT in the System Folder, it is disabled anyway.

When booting from a hard disk or floppy disk, and then wishing to use an Iomega Zip drive, conventional wisdom is that you require the Iomega driver for formatting and mounting. As I will verify below, this is *not true*.

I repeated my previous formatting experiments *without* an Iomega INIT using the same third party formatter. Low level formats succeeded but an error was reported during the initialisation stage. After a reboot, the Plus recognised that there was a cartridge in the drive, and offered to initialise it. (Note that this is an extra stage when compared to the same procedure *with* the Iomega INIT.) After the second initialisation stage, I copied the System Folder and successfully booted.

I also tested booting from a hard disk and ejecting/remounting a Zip cartridge that had been formatted *without* the Iomega INIT. Everything worked fine, confirming that the third party formatter had installed a decent media level driver that identifies a Zip cartridge as removeable media.

Additionally, I took a formatted, booting Zip 100 cartridge and inserted it in a PowerMac running OS 9.1 with a later Iomega Zip extension (version 6.06). For the sake of it, I copied a few files onto the cartridge. I then tried to boot from the cartridge in a Plus, but the System Folder had been clobbered by OS 9.1, so it was no longer bootable. I reblessed the System Folder and it booted again.

My conclusion is that the Iomega INIT is not required during formatting on a Plus, but may be helpful to my third party formatter (Anubis). This obviously need testing with other formatters. One more test to do, unless anyone has any bright ideas...

 

[Charlieman]

The last test I did last night:

Format a Zip cartridge using Anubis *with* an Iomega INIT. I then tested ejecting and reinserting the cartridge *without* the INIT installed on the main hard disk. Disk reinsertions failed to work. Perhaps a version of SCSI Probe or similar might work for this functionality.

Finding a formatter that will work with System 6 (especially with a 1MB Plus) is the hard part. Lido 7.5.6 struggles to run in 1MB and Micronet 7.1.9 dies completely. It may be easier to use a higher spec Mac to perform the format and initialisation, before attaching the Zip drive to the Mac Plus. I'll carry on playing for a bit (Silver Lining looks good for the Plus and System 6) and write up my notes in a more coherent fashion shortly.

 

[Mac128]

However, I am using pre-used cartridges that have various media drivers on them. The low level format is essential to remove any evidence of that driver. Otherwise we end up with the well reported problem with Pluses being unable to use or format cartridges that have been "updated" with a later media driver.

Yes I was using recent PC formatted cartridges, so they were not recognized by the Mac without the Iomega Init in the System folder, but were easily re-formatted with Iomega's 4.2 Zip Tools under System 6.

As for the updated driver problem, I thought the main issue was having to reformat the disk with the 4.2 driver Tools, meaning back it up and re-initialize, a real pain either way. All of my old Zip disks were updated to newer drivers at some point back in the day before I knew about this problem. However, I have since successfully restored all of them to bootable 4.2 drivers using the 4.2 Zip Tools alone (under OS 8.6 no less).

Also, I presume you formatted the Zip 250 disk with a third party utility and not the Zip tools which would require System 7 and likely not be recognized by the Plus?

This may be of some help with third party formatters from Michael Peters's defunct website:

This app uses the SIOUX console library

Choose 'Quit' from the file menu to quit.

 

Use fake disk names (/dev/scsi.; i.e. /dev/scsi0.1, /dev/scsi1.3, etc.).

 

Top level command (? for help): l /dev/scsi0.5

finding devices .......

 

Partition map (with 512 byte blocks) on '/dev/scsi0.5' (/dev/sdb)

#: type name length base ( size )

1: Apple_partition_map 80 @ 1

2: Iomega_DiskInfo 10 @ 81

3: Apple_Driver* 400 @ 91

4: Apple_HFS 196106 @ 491 ( 95.8M)

5: Iomega_backup 1 @ 196597

6: Iomega_DiskInfo 10 @ 196598

 

Device block size=512, Number of Blocks=196608 (96.0M)

DeviceType=0x0, DeviceId=0x0

Drivers-

1: @ 91 for 4, type=0x1

 

Top level command (? for help):

 

[krye]

Anyone know why my Zip 100 with System 7.5.5 installed boots up my SE no problem, but not my Mac Plus? The Mac Plus powers on. For a second I get a smily face, but it then turns to a question mark after a few seconds. I have the Iomega 4.2 INIT in the system folder, but I thought you didn't need any INITs to boot a SCSI device.

 

[Mac128]

Anyone know why my Zip 100 with System 7.5.5 installed boots up my SE no problem, but not my Mac Plus? The Mac Plus powers on. For a second I get a smily face, but it then turns to a question mark after a few seconds. I have the Iomega 4.2 INIT in the system folder, but I thought you didn't need any INITs to boot a SCSI device.

The Zip drive itself has to have the 4.2 driver formatted on it (i.e. not in the System folder which does not need it to boot). Depending on what Zip INIT you are using on the SE System, or other Macs, there was a nasty habit of the ZIP INIT updating the ZIP disk without asking if the INIT was newer than that installed on the disk.

You could also have termination issues. I believe the Mac Plus does not provide termination power but the SE does.