Micronet SCSI Utility Problem

>I know that the Macintosh Plus requires interleave 3 or 3:1.

Yes, that is the normal setting for a Macintosh Plus. However, depending on the hard drive and its buffer capacity, it may or may not work with a smaller interleave.

>The Micronet SCSI Utility will not let me do that.

You may want to test other formatting utilities (such as Lido 7.56, which needs around 300K disk space). Normally, you should let the utility handle the complete operation with formatting and hard disk driver installation (with the hard drive is connected to the Macintosh Plus). Do not use customised partitions at this point.

>Should I use the Apple HD SC setup instead?

Apple HD SC Setup was designed to handle hard drives with an Apple ROM, and would not (at least not unmodified) work with third-party devices.

>Do I need to have a battery installed?

A Macintosh Plus should boot without a battery installed.

>Maybe it won't boot because I have no proper way to install System 6, other than dragging the system folder on to the hard drive icon on the desktop.

In principle, that is OK. The System Folder should have a little Mac icon. If necessary, one can try to drag the Finder out of the System Folder, then close the System Folder, and finally drag the Finder back in.

Do you have another old Macintosh computer to work with? The ideal situation would be to have a second pre-1998 Mac, with a built-in floppy drive (that can handle both 800K and 1.44 MB), a SCSI port, a CD-ROM drive (internal or external) and Ethernet. That would allow you to handle downloads/transfers from more modern machines (Mac or PC). With Disk Copy 4.2 and/or 6.3.3 installed, properly sector-copied floppy disks could be made from disk images whenever required.

Which System 6 version do you have? For users with a Macintosh Plus with only 1 MB of RAM, System 6.0.3 would be appropriate. If you wish to carry out a complete installation of a later version, or System 7, do install more memory (the total maximum is 4 MB). Also, we cannot rule out that the limited amount of RAM may affect the operation of certain disk utilities.

Sorry, I do not know exactly what is causing the error message. You will just have to carry on with tests. Try all the available disk formatting utilities until the hard drive (hopefully) is working OK.

The Finder should be in the System Folder. The moving back and forth is only necessary if the System Folder does not show a Mac icon.

Error code lists seem to indicate that this is an "Unimplemented Core Routine". Unfortunately, that does not tell me much in this very case. Are you still running the computer with 1 MB of RAM (or have you installed the new modules for a total of 4 MB)? If 1 MB, we should perhaps not rule out that it possibly could be insufficient for the utility. Was the received floppy with the utilities bootable, or did you somehow have to copy Lido 7.56 to an existing (System 6.0.4?) startup floppy? The lowest supported/possible operating system version for Lido 7.56 is not known to me.

Since you appear to have tested all formatting applications with a System 6.0.4 or lower, it would perhaps not be a bad idea to try a later operating system version startup disk (for example, a System 6.0.8 utilities floppy, or a System 7.0 disk tools disk).

Could it possibly be that interleave 1 is sufficient because of the hard drive having an adequate buffer capacity?

There were certain problems related to different ROM versions ("Macintosh Plus ROM Versions" under the date 1987-07-01 at https://developer.apple.com/legacy/library/navigation/). I do not know whether this is of importance here, though.

>Are you saying that the hard drive is the problem, not the computer or software?

The Macintosh Plus is a bit special compared to the later Macintosh computers. As I understand it, the Plus has a limited ability to control sending and receiving data to a SCSI device. That would require an old hard drive to be formatted with an interleave 3 (thus slowing down the transfer). An exception seems to be if a hard drive has an adequate cache (buffer capacity), which apparently is the case with many slightly more modern SCSI hard drives. So, the question is whether there would be a problem at all if interleave 1 is used.

>Interleave 1 must not be sufficient because the computer won't boot from it, unless there is another problem.

Interleave has something to do with the ability to transfer at a certain speed. The ability to boot or not is something else.

>If the problem is in the ROM, where can I get a later version ROM chip?

I do not know if ROM has anything to do with the computer's behaviour in this case, and whether a different version would affect matters. Is your Macintosh Plus an earlier beige or a newer platinum model (see the aforementioned Technical Note "Macintosh Plus ROM Versions")?

>Perhaps I must change the drive ID? The ID is set to 6 right now.

The SCSI ID should not be important, as long as it is between 0 and 6 (and no other device has the same number).

Addendum

>>Interleave 1 must not be sufficient because the computer won't boot from it, unless there is another problem.

>Interleave has something to do with the ability to transfer at a certain speed. The ability to boot or not is something else.

However, difficulties reading from and writing to the hard disk could of course lead to incomplete/delayed data, which might cause boot issues.

Sorry, I do not know whether the boot problem could be related to interleave, cache/buffer, hard disk drive driver software, ROM, or something else. It is probably not going to change anything, but a PRAM reset can always be tested. You will just have to keep on experimenting. Good luck!

It would also be interesting to see if a SCSI Zip 100 drive (Zip 100 disk) behaves in a similar way (http://www.vintagemacworld.com/pluszip.html). Zip drives are usually relatively inexpensive. BTW, an extra USB Zip 100 drive would allow file transfers from/to a more modern computer (even a PC, with the proper method/software).

>I Have a beige Macintosh Plus, most likely converted from a 128k, 512k, or 512ke.

Normally, that should mean one of the two first ROM versions mentioned in the technical note above (but we do not know if a possible conversion has changed this).

>How would I perform a PRAM reset?

Under System 6.0.8, start the computer. Wait until the Desktop can be seen. Now, press and hold the three keys Command + Option + Shift (in the lower left corner of the keyboard) and then choose Control Panel from the Apple menu. A dialogue box will appear; click Yes.

>Is there a way to check how much buffer capacity the cache has?

None that is known to me, but you may want to post the exact IBM hard drive name/model/type in order to make it easier to search for relevant information.

>What would prevent various formatting utilities from formatting to an interleave other than 1 or 0?

Just guessing, but we should perhaps not rule out that the formatting utilities read configuration data from the hard drive, and that this somehow would create limits. Since you obviously have installed a system on the hard disk, which apparently is working OK (apart from booting), it may well be that everything already is fine as far as the formatting is concerned. What about various drive test options in the utilities? Do the programs report any hard drive errors at this point?