4

Attempting to upgrade Mac OS Classic 7.5.0 to 7.5.3 via floppies that have been tested successfully on a Performa 460... but things fail ominously on my IIsi with "This is not the correct "⟨SrcDisk⟩" disk. Make sure you are using the original Installer disks and try again. Click Continue if you have the correct disk to insert. Click Stop to stop any further installation."

eIIsi install failure

Some kind of copy protection? What gives, these install floppies just worked yesterday on a Performa 460 just fine, where is this error coming from?

3
  • 1
    Different installers for different models? Commented Oct 18, 2022 at 3:33
  • 1
    I don't think so - the advanced mode installer lets you select the system, both are listed. I installed in easy mode however (let the installer decide), I may as well try and force it... will let you know what happens.
    – 0xF2
    Commented Oct 18, 2022 at 12:55
  • 1
    Selecting the narrow IIsi system set generates the same error. No difference.
    – 0xF2
    Commented Oct 22, 2022 at 1:15

3 Answers 3

4

There is no copy protection in System 7.5.x. Even in the era of its original release, Apple distributed it for free on the Internet.

The Apple Installer 4.0.3 Error Guide p.10 gives this description for the "The installer document [...] is unusable for installation" error message:

This error occurs when the Installer is unable to find a required resource specified in the installer script - 'inrl', 'inpk', 'infa', etc., has become corrupted, or the resource map has become corrupted. This error has also been known to occur due to the following reasons.

  1. Two packages are included for installation which involve conflicting actions. One package calls for the installation of a file or resource, and the other package calls for it's deletion, if it exists.
  2. The same source resource is specified for installation as two different resources under separate resource ID's. In other words, there are 2 'inra' resource which reference the same source resource, but specify different target resources.

From the description, it sounds like the several possible causes can lead to the error, maybe corruption of the Installer Document itself (in the Installer-related resources), or maybe corruption of some other resource or file they reference, besides the numbered installer design errors noted.

The most obvious cause would be data corruption, either of the disk itself, or due to some hardware problem with the machine that causes it not to be able to read the disk correctly (malfunctioning floppy drive, logic board, RAM, etc.)

The inrl resource contains "Installer Rules", logic which is specified in a kind of scripting language and the installer will use to implement automated behaviour such as for Easy Install and which can include actions for specific machines. (See Apple Installer 4.0.8. Technical Guide, p.80).

This is speculation, but due to the parts of the installer that this error is related to being possibly machine specific, maybe there is corruption in a part that just isn't used in the installation on the Performa 460 and so didn't come up there.

Someone who has the capability to figure out the details of the Installer Rules from the binary compiled versions in the inrl resources may be able to shed some light on what's present on the IIsi and absent on the Performa 460 or vice versa.

6
  • 1
    In case you're short of workarounds, a thing to try to rule out hardware disk causes would be to try mounting Disk Copy images of the installation disks instead of using actual floppies, though you'll need a spare disk/partition to have them on during the installation and some way to transfer them on (CD-ROM, network, serial, etc.)
    – rakslice
    Commented Oct 20, 2022 at 7:59
  • It might be a good idea to put all helpful information into the answer, not part in comment.
    – Raffzahn
    Commented Oct 20, 2022 at 8:11
  • 1
    Is there a way to check for corruption? A checksum of some kind? Are parts archived/compressed with a tool that can check them? Is there a way to get a debug console during installation? Commented Oct 20, 2022 at 8:24
  • 1
    @hippietrail I don't know if there's a good way to do that; my bad way, which only works for write-protected disks where you're not expecting any changes at all, would be to image any physical disks back on different machines with Disk Copy and compare the checksums Disk Copy reports with the other machines and with the checksums of known good copies of the images
    – rakslice
    Commented Oct 21, 2022 at 20:22
  • 1
    @rakslice your workaround with disk copy local mounts worked really well.
    – 0xF2
    Commented Oct 28, 2022 at 19:14
1

My suggestion would be to download the disk images to your Performa 460 and make a fresh copy of the problem disk on other media.

If that works and you want, refresh the apple provided disk with the image to determine if the media itself has failed. Eventually it is likely that the surface of the disc will be unable to retain data.

1

The cause of the error in this case turned out to be a degrading floppy disk drive.

Unreliable reads from the floppy caused the arcane error message.

1
  • 1
    What you need to understand about the drive is that it is unlikely bad but rather out of calibration. Floppy drives are not precision devices and if the heads are on one edge of the track area, while the disks were written with a drive whose heads are on the other side of the track area, you will get similar errors. Neither drive is 'bad' Commented Nov 11, 2022 at 0:47

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .