<Well . . . here we go . . . the fact that N* memory mapped their FDC was on <thing that clearly would fall in the MISTAKE category. What the reason fo <the existence of the smaller TPA resulting from memory mapping anything is the TPA bit was something I could care less about. The memory mapped design was functional, not pretty. Of course the first controller I'd built was IOmapped not for more space but because it was easier to decode 8bits rather than 16. Was it the right way for them, not really but it worked. there were plenty of other memory mapped designs that were not nearly as nice. It's the way it was right or wrong. So happens I have two and one replaced my altair. It was a damm sight better and reliable depite two lightiing hits. The only design fault I sought to fix was the lack of storage denisty, 80k per drive was far from enough. The later controller and software was an improvement but hard sector was a problem as it was not even remotely portable. The processor card and the IO on the backplane was however very nicely done. Like many I used third party ram mostly because I'd alreay had 32k of SEALS 8k static from the altair. I still do not ahve NS* ram for the odler box, I'd put in a Compupro Ram-16 back in '84 to get rid of the six 8k static and a 16k static. Such is the evolution of just one system. <of no relevance. It was a justification for SOME of us, me included, to <draw a line through their products whenever they appeared in a list. Of <course their price would have been another. It was their price that made them attractive. Least on the east coast. Some systems like CCS I'd never seen until a few years ago. Others were a bit rich price wise or questionable vendors. Allison