Target mode between Macbook pro 2017 and Mac Pro 1.1

A likely reason is that the new file format used on your MacBook Pro with High Sierra is unreadable to older Macs running previous macOS versions. Read about Target Disk Mode here: How to use target disk mode to move files between two Mac computers - Apple Support.

John Galt wrote:

A likely reason is that the new file format used on your MacBook Pro with High Sierra is unreadable to older Macs running previous macOS versions.

Wouldn't that mean Target Disk Mode will no longer work to transfer data from a Mac not running High Sierra to a Mac running High Sierra? You'd think Apple would mention that.

John Galt wrote:

That's not what I wrote.

No it's not. I just don't understand why someone would be transferring data from their new Mac to a much older one. So it didn't seem like "a likely reason". Not a big deal.

Sounds like that’s not working. If the older Mac can be set up for sharing files and the new one also for sharing.

1. Make a LAN setup you may already have one

2. You can hook up an ether net cables between the two; pretty sure Mac OS X can negotiate without the need for a crossover cable.

Then you can pull the data you need.

Lou Cioccio

When you say "usb-c to thunderbolt adapter", do you mean "thunderbolt 3 to thunderbolt 2 adapter"?

That is the only one which ought to work.

New MBP <--TB3-TB2 adapter--><--TB2-Firewire adapter--><--FW800-FW400 cable--> Old MP

ought to work, even though it is a kludge.

Two other alternatives, from least expensive to most expensive:

1) Take the bare drive(s) off the Mac Pro (which is easy enough to do) and insert them into a USB-C or USB3 Hard Drive Dock device.

2) Use a Thunderbolt3 Dock from OWC, which among many other ports has a FW800 port, and connect the FW800-FW400 cable to that to use the MP in target disk mode.

I don't see any info about connecting USB-C to Firewire on this page.

How to use target disk mode to move files between two Mac computers - Apple Support

That's not what I wrote.

I don't understand either.

What really (doesn't) happens is not clear. The Pro hd doesn't mount on the mbpro's desktop?

What OSs on each machine? Please note that less infos you provide much difficult is to help you...

Assuming that the Mac Pro is really in target mide (big icon bouncing on the screen) my verdict is: always hathed adapters. I believe the problem is there. Hope somebody else can help you.