Hi Glen and Joe, Thanks for your replies. I've had a closer look at the controller / computer / terminal connections. It seems to work something like this The 2648A terminal has a 13260A card that is connected via a short hooded edge connector and cable to a longer hooded edge connector on the rear of the 'controller' box. The controller box is then connected via another cable (that I have) to a 12531 card the HP 1000 computer. The long hooded connector on the controller has the same number of contacts as the 12531 card in the computer - so I would assume that it is just replicating the contacts in the computer. The controller box has a number of short-cut keys for various functions that the system can perform so I would guess that the controller can inject characters into the connection between the terminal and the computer. My memory is that all the funcions have two character shortcuts that can be typed in at the terminal and I notice a couple of cards with diode matricies in the controller. There is a diode array for each key consisting of up to 16 diodes - 2 lots of eight bit ascii - maybe. Anyhow, Glen it looks as though your cable detective work is correct. The cable is a 13232B p/n 02640-60058 for connecting the 2648A to a 12531 interface. Joe can you please have a fish around and see if you have the right cable + we can work something out. If not then I'll have to take the build-it-yourself approach. Many thanks to you both. Peter Brown _________________________________________________________________ Surf together with new Shared Browsing http://join.msn.com/?page=features/browse&pgmarket=en-gb&XAPID=74&a…