<I can repair the RAM 16 A3 but I don't have the switch settings and <jumper settings (J) to set it to start at 2000H. What are these? Is that a NS ram 16? I have a mod of the MDS-A3 (SD) controller to put Phantom/ on the bus. However the card has to respect it. The address hole needed for the controller is from E800 thru EFFFh. <Also, I have a RAM 16 A2 board that I can try. Are the switch settings <and the jumper settings on it the same as the A3 to start at location <2000H? Dont ahve them for that card. Never used any of the NS* ram cards. <Finally, will NSDOS run in 16K ram? I see no indication in the manuals <that it won't but it's a good question to ask anyway. NSdos runs fine in 8k! the dos is d00H (DD 3328) or a00(SD 2560) large and starts at 2000. Basic however does fit in 16k but barely. So happens I'm resurecting a NS*Horizon I got a few weeks back. Mine is however working just fine once I set up the serial for my standard setup and to match the Horizon I've had for 21 years. Allison