Unfortunately he doesn't have any cable for sale, and I don't know where to buy it. I wonder ... is there a guide or an hack to make an homemade one?
One alternative is the embedblog adapter here
http://embedblog.eu/?p=475. Schematic and 3d-print are free and he also sells the unit for very reasonable 10 EUR. The ATTiny adapter expects a BM869S for signal decoding, but you can configure it to send raw data to the USB port. This way it will work with almost all Brymens.
I purchased one myself for a BM829s and configured an Excel spreadsheet to translate the raw data. Works very reliably and gives me more flexibility than with the original cable.
Patrick