Hi Dwight - seems we have several interests/machines in common. I used to have an early Horizon in the blue metal (no wood) box - gave it away years ago, which I regret - would love to be able to build up another one, so if at some point you decide you have too many boxes (metal or wood) - please think of me - I still have a spare SD controller and a few other N* parts. I wrote a transfer program for the N* SD controller in order to extract the disk images for my Altair simulator (I'm running the N* SD controller in the Altair) - All it needs is a bit of tweaking to allow it to handle DD disks. I've got tons of native software that I wrote for the N* system, and a few other utilities (the PC->N* binary input program I mentioned in previous post, as well as utilities to transfer files directly into and out of N* disk images) - I have no idea how many people are still into N*, but perhaps we should think about creating a pool of resources such as we have for the H8 - If enough people are interested. I assume you know the right (and wrong) things to do - if not, contact me off-list and I can provide some pointers. I've got tons of SD software (much of it my own) - and I know a few people running DD horisons - I'm sure we can get you setup with usable software. Btw, in doing my Altair project, I contacted Dr. Charles Grant - the surviving founder of NorthStar, and he granted permission to distrubute and use all of the NorthStar material - I have the SD software and many of the N* manuals posted on my web site. It would be a fairly simple matter to tweak my Altair simulator into a Horizon simulator - mainly removing the front panel support and modifying the I/O map... Regards, Dave -- dave04a (at) Dave Dunfield dunfield (dot) Firmware development services & tools: www.dunfield.com com Vintage computing equipment collector. http://www.parse.com/~ddunfield/museum/index.html