Mac 2018 21 ; how to connect to a firewire. 800 external drive

Maybe you have USB-A connectors here, and not FireWire? The last iMac models with FireWire were sold in 2007 or so; they’re pretty old, and that’s also before 4 TB HDDs were fairly common.

Here is a common USB-A connector:

Here are the shapes of the FireWire connectors, though FireWire 800 will have more pins than is shown.

If these really are FireWire, then USB sled will allow you to gain access to most hard disk drives, though that’ll require removing the HDDs from the enclosures and re-mounting them in the sleds.

Here is a chart of the common connectors:

https://en.wikipedia.org/wiki/USB#Connector_type_quick_reference

If these HDDs are USB-A as I might suspect, Apple sells an adapter for USB-C to USB-A here:

USB-C to USB Adapter - Apple

Somewhat unusually for USB-C to USB-A adapters, this particular adapter also provides enough power for SuperDrive and some other higher-power-requirements USB-A gear.

[Images from Wikipedia.]

As others have mentioned, removing the drives from their enclosures and putting them into a USB dock or a USB enclosure would seem the best temporary, cost-effective solution.

If you're looking for a longer-term low-cost solution, the 2012 Mac minis include a Firewire 800 port and USB2/3 ports.

I use a 2012 Mac mini i7 quad-core connected to my HDTV, using two daisy-chained Firewire 800 Time Machine backup drives. I've upgraded the mini internal drives multiple times, most recently with 1TB SSD's, but the ancient Firewire drives still are working reliably!

OtherWorldComputing (macsales.com) still has a few 2012 Mac minis for sale, beginning at less than $100, depending upon processor, memory, and drive configuration.

carolweavee wrote:

One is a 4 TB drive that connects with a 800 FireWire

What is the make and model is this external drive..?

If it does not have an additional USB port..?

Then you would be better off finding someone with a Mac that has FireWire and transfer the data to a USB drive.

The other is a 3 TB that connects with what I believe is a USB2 (it’s a sort of square end).

Sounds like you need a USB-A to USB-B 3.0 cable for this external drive.

for example > https://www.amazon.com/Amazon-Basics-4-8Gbps-High-Speed-Gold-Plated/dp/B00NH144GK/ref=sr_1_4?

Per MrHoffman's response, you can use either one. Just transfer the drive from the Firewire enclosure to either USB enclosure.

Unfortunately, there is no way to convert a Firewire device to USB or Thunderbolt. I've looked many times, and even purchased a couple of cables/converters that were supposed to work. They didn't.

Firewire requires more power than USB can provide. Attempting to use any type of converter usually results in the Mac displaying a warning that the USB port you tried to use was shut down to prevent damage.

I hoped I could at least find a multi-port hub that could supply both USB and Firewire their required voltages so it could then act as a bridge for transferring data. No such hub seems to exist. Or I should say, I found a few, but they were discontinued quite a while ago and are no longer available as a new item.

Here's one of them. One USB and one FW400 port input each in the front. Four USB and one FW400 input in the back. Then choose either a FW400 port out to the computer, or USB.

This IOGEAR unit seems to be a similar device.

For either one, you'll also need a simple FW800 to FW400 converter.

Both of those have USB 2.0 connections and should have come with a USB cable. That USB cable will plug into your newer iMac's Thunderbolt/USB 3 ports using a USB-C to USB-A adapter.

For some examples:

USB-C to USB Adapter - Apple

https://www.amazon.com/dp/B08Z768LCW/ref=sspa_dk_detail_1?

https://www.target.com/p/philips-usb-c-to-3-0-usb-a-female-adapter/-/A-79804275

Those are both USB-capable drives. They’ll connect to USB-C with the adapter I mentioned.

You're welcome. Glad to hear you were able to complete your project.