Memory manager error at Macintosh Classic

Some earlier models had a wire that actually had to be cut when adding RAM. We added RAM to our SE. 2Meg would not work without alterations but 4 meg would. At $100 per meg of RAM, that was a serious choice of upgrades.

Have you tried going back to 2 meg to see if it goes back to working fine? If not, you have introduced a new element to diagnose. Sounds like you can not boot from a floppy. Can you boot from an external SCSI device?

Are you starting up with the 'shift key' down to call up 'extension manager' before loading Finder?

Hi Stelios,

Since the Classic appears to boot properly from ROM, the problem seems to be with the operating system installed on the hard disk. Normally, you would just reinstall the system software. However, a faulty floppy drive makes things more difficult.

As Jim indicated, an external SCSI hard drive could really have solved the problem. Without one, you would probably have to experiment with removing the internal hard drive from the Classic instead, and somehow (with power properly supplied, and with correct ID settings) try to connect it to the SCSI port of another older Mac (perhaps the 7200/90 that you mentioned under an earlier topic).

Jan

Alternatively, the hard drive in the 7200/90 could be replaced by the Classic hard drive. The following is an experiment. It may or may not work as intended.

First, (using the Make a Floppy command in the Utilities menu of Disk Copy 6.3.3) create one Disk Tools PPC floppy and one Network Access Disk 7.5 floppy:

http://download.info.apple.com/Apple_Support_Area/Apple_Software_Updates/English -North_American/Macintosh/Utilities/Disk_Copy/Disk_Copy_6.3.3.smi.bin

http://download.info.apple.com/Apple_Support_Area/Apple_Software_Updates/English -North_American/Macintosh/System/Mac_OS_8.1_Update/Disk_Tools_PPC.img.bin

http://download.info.apple.com/Apple_Support_Area/Apple_Software_Updates/English -North_American/Macintosh/Utilities/Network_Access_Disk_7.5.sea.bin

Start the 7200/90 from the Disk Tools PPC floppy.

Create a new folder on the hard disk (call it 'Deactivated Classic system'). Move the entire existing System Folder on the Classic hard disk to this new folder. Rename this System Folder (call it OLD1System Folder). Move the System suitcase out of the OLD1System Folder. Place the System suitcase next to the OLD1System Folder inside the 'Deactivated Classic system' folder.

Next, drag-copy the System Folder from the Disk Tools PPC floppy onto the hard disk. This will create a temporary system on the hard disk. Shut down the computer.

Start the 7200/90 from the hard disk (disregard any message about the system, click OK). The floppy drive will now be free.

Create a new folder on the hard disk (call it 'Deactivated system 8.1DT'). Move the System Folder (the one that originally came from the Disk Tools PPC floppy) on the hard disk to this new folder. Rename this System Folder (call it OLD2System Folder). Move the System suitcase out of the OLD2System Folder. Place the System suitcase next to the OLD2System Folder inside the 'Deactivated system 8.1DT' folder.

Finally, insert the Network Access floppy (while the computer is still running from the hard disk). Drag-copy the System Folder on the Network Access floppy onto the hard disk.

At this point, you could also insert other floppy disks and copy various files (for example, StuffIt Expander) to the hard disk.

Finally, move the hard drive back to the Classic. The new (Network Access 7.5) system will provide very basic functions (but may allow networking via a MiniDIN-8M to MiniDIN-8M printer cable to the 7200/90 for subsequent file transfers).

Hello again,

I should add that the above has not been tested with this combination of computers, so it would really be an experiment if you try it.

Do not connect/disconnect external SCSI devices while a computer is running. If you have to replace anything inside, always switch off the computer and disconnect it from the mains. Since you already had added RAM in the Classic, I have to assume that you know exactly what you are doing, and that you are fully aware of all safety procedures. As you then know, working inside a compact Mac can be very dangerous because of the high-voltage circuits involved (various components can also hold charges for a long time after the computer has been switched off and disconnected).

Jan

BTW, I suppose that the memory installation has been done in accordance with the following article:

http://support.apple.com/kb/TA44709