Hello,
You’d need to obtain some video hardware that can output to a monitor.
Did you find a solution in the end?
There are some suggestions on the Media 100 website in the Frequently Asked Questions section:
https://www.media100.com/pages/frequently-asked-questions-media-100-suite-v2-1-8#hardware
You could simply get a Thunderbolt to Firewire adapter from Apple, and do exactly the same as you used to – however, Firewire only gives you a choice of DV or HDV out.
The BlackMagic Ultra Studio Mini Monitor is the most popular piece of hardware for attaching a video monitor to other editing suites, and unfortunately is not supported by Media 100;
instead, there is support for more fully fledged i/o hardware, such as the AJA IO XT and the BlackMagic UltraStudio 4k – both of which can connect to your cylinder Mac Pro via Thunderbolt.
The Intensity Pro referred to in the FAQ, is the older card you put inside an older Mac Pro tower, and not the modern shuttle versions that work via thunderbolt – I do not know if those work yet. They might. If you get one, let us know, =).
Some people are using older AJA or BlackMagic cards via a Thunderbolt PCIe chassis too. The FAQ mentions the Sonnet’s Echo Express SE II.
Media 100 is free to download these days,
so you can ask the sellers of any equipment you’re considering buying,
to download Media 100 and see if it works with it first,
before splashing your cash, =).