Greg it might be worth trying another computer to mount interface to eliminate the shoestring this outfit in Melb sells a TTL/usb device that does the same job as the Shoestring, it is a quarter of the price of the shoestring,
https://www.shop-dontronics.com/usb-...onverter-cable
You will need to buy a db9 plug from Jaycar and replace the header with the db9, details are on the page, or here-
http://eq-mod.sourceforge.net/tutindex.html