HP Pioneers ROM dump

[chapotito]

Ok, I am new to posting questions. This may have been covered, I just cant seem to find it. I have been trying to dump my 27s and cant seem to follow step 5.1 on that HP Pioneers ROM Dumping PDF file from an article last on 03-01-2017 published by Jose Mesquita. I am new to this, so be patient. How exactly do I start writing in the 27s memory editor? What do I have to press firs?. I am able to navigate to the address recommended, the 52000, but after that I am completely stumped. It says to write the program, but I have no idea what I have to press. For example, how do I enter D5 on the first address if every key I press moves the address? Also, how do I write letters if I cant access alpha mode. Is there a manual somewhere that I can access to learn these things?