New finds and a question

After a very poor start, my weekend ended up great - I picked up three Apple IIc's (which I didn't want as I already have two) for $10, but they came with some thirty manuals for most of the Apple II range (along with the Osborne Executive) and a number of books on the Apple IIs. Thinking this made for a good day, I was later given a Microbee with the Computer-in-a-Book drive,and a Dick Smith System 80. The Microbee was an Australian Z80 CP/M system, highly sucessful both as kits (as they originally were) and complete systems, especially in schools. I had been searching for one for a while, but had very little luck - everyone I knew who had one was too attached to it to let it go. The System 80 was a TRS-80 Model 1 clone, with some interesting modifications - most notably an inbuilt tape deck. Another computer I had been specifically looking for. :) Anyway, as to my question. The System 80 works fine, but it seems it needs a cable to connect to the monitor. The monitor uses a standard TV aerial connector, but the computer has a DIN. Fortunately I found a technical manual for the computer in one of my piles of manuals at home, and it lists the pin outs - one +5 volt, one ground, and one video output. It also has a diagram of the cable, and it seems it is just a plain cable with different plugs at each end. Knowing nothing about electronics, it seems to me that the TV plug has only two contacts, not three - anyone know how I make the cable? Or know where I might find a replacment? I'm sure this is a really stupid question but I am a mere programmer - technical stuff is way out of my league. Thanks heaps, Adam.