Mac Plus connect to USB drive?

A USB drive cannot be used with a Macintosh Plus. If an external hard drive is needed, you would have to look for another SCSI drive.

A Zip 100 SCSI drive could perhaps be an alternative. That way, it would also be possible to transfer files from/to a Zip (100) USB drive connected to a more modern computer, if necessary.

The Floppy Emu (floppy and hard disk emulator) could be another option in this case.

Please note that software diskettes for a Macintosh Plus would be in a special (400K or) 800K Mac format, and cannot be read in a USB floppy drive. A second pre-1998 Macintosh computer (with a built-in floppy drive) would be required for the handling of such disks (for example, in order to create a modified startup floppy for the Plus).

Hi,

Yes, unfortunately, SCSI drives are often expensive.

You mentioned an external SCSI drive. Would it be correct to assume that the external enclosure is OK, whereas the hard drive inside is not working? Any chance of locating another SCSI drive to be placed in the enclosure? Sometimes older hard drives suffer from "stiction". If so, knocking on or swinging the drive may lead to a change. One could even open a faulty drive in a last attempt to recover files (information about manually assisting non-working actuator arms etc can be found on the Internet).

Alternatively, if you can find a PowerBook with SCSI Disk Mode support (such as PowerBook 160/165/180/180c or 520/520c/540/540c), that computer could be used as an external hard disk:

https://manuals.info.apple.com/en_US/0302674APB160180UG.pdf (page 230)

https://manuals.info.apple.com/en_US/PowerBook_500series_UserGuide.pdf (page 31)

Today, I carried out an experiment with a PowerBook 540 (normally, running System 7.5.3) connected to a 4 MB RAM Macintosh Plus. After having deactivated the 7.5.3 system, a System 6.0.3 system folder was copied to the PB 540 hard disk (System 6.0.3 is merely an example; other versions possible). All devices were then switched off in order to allow the SCSI cables to be connected. Since termination power can be a problem in a similar setup, an external Apple CD-ROM drive (without a CD) was made part of the SCSI chain for this experiment (may otherwise not be necessary, depending on computers, cables and terminator types involved). The special 30-pin HDI-30 adapter forces the PowerBook into SCSI Disk Mode when powered on.

When the Macintosh Plus was switched on (no floppy in the floppy drive), it then booted to System 6.0.3. The entire PB 540 hard disk was visible at the Plus.

It is important to have access to an appropriate startup floppy, such as the Network Access Disk 7.5 (http://download.info.apple.com/Apple_Support_Area/Apple_Software_Updates/English -North_American/Macintosh/Utilities/Network_Access_Disk_7.5.sea.bin), in order to be able to regain control over the PowerBook (that is, reactivate the normal system on the hard disk) after a test like this; a PB 540 cannot boot to System 6.0.3.

I know this is a while after your post and I apologize - if you don't mind spending a little money, this is well worth it...

https://www.bigmessowires.com/shop/product/floppy-emu-deluxe-bundle/

• Macintosh Floppy – 400K, 800K, and 1.4MB disks
• Macintosh Hard Disk – HD20-type disk volumes up to 2 GB

😐 mac os x pro 1.1 ,? 2.1

I have seen SCSI to SD card adapters that allow OS to be run from an SD card instead of the original hard drive, and allowing for easier file transfer.