Thought I'd give it a spin with PrintMaster on the Amiga.

I tried with the cpc6128 and I was able to start Printmaster using the cpm startup disk with typing "|cpm", but it required a thousand disk swaps and it seemed to have trouble handshaking and dropping characters (even with my buffer). Oddly on the 6128, the arrow keys wouldn't work with Printmaster unless I held down the left arrow key and keeping it pressed, pressed the right arrow key.

As far as I can tell, the Amiga does watch the ack and busy lines and won't send any data while the printer isn't ready.

[Linked Image from i.imgur.com]