Well, Able made a thing called an 'Able ENABLE' which allowed use of more than 256KB of physical memory on any UNIBUS -11 with memory mapping hardware which wasn't an -11/70-44-24. That's probably what it's talking about.

We had one on our -11/45 at MIT, BITD. So I have the programming spec for it, back-created from the source code for that machine. And Clem Cole was nice enough to follow up on an old message in an email list archive, and dig up some documentation and scan it in. I was planning on doing a page for it on the Computer History wiki, haven't got a round tuit yet, though. They are, AFAIK, complete unobtainium in physical form; I've been looking for years, never seen one. If someone wanted to upgrade SIMH to support it, we do know enough to do that. Noel

Well, Able made a thing called an 'Able ENABLE' which allowed use of more than 256KB of physical memory on any UNIBUS -11 with memory mapping hardware which wasn't an -11/70-44-24. That's probably what it's talking about. We had one on our -11/45 at MIT, BITD. So I have the programming spec for it, back-created from the source code for that machine. And Clem Cole was nice enough to follow up on an old message in an email list archive, and dig up some documentation and scan it in. I was planning on doing a page for it on the Computer History wiki, haven't got a round tuit yet, though. They are, AFAIK, complete unobtainium in physical form; I've been looking for years, never seen one. If someone wanted to upgrade SIMH to support it, we do know enough to do that. Noel