At 1:03 AM +0200 7/15/11, Johnny Billquist wrote: RSTS/E and RSX-11M+ (as well as Unix) do require an MMU, and some additional things to run though. RSTS/E offers some real challenges if installing on real hardware. While I've installed RT-11 and RSX-11M+ off of CD-ROM, I'm not sure it's possible with RSTS/E. Another tricky situation I ran into was that RSTS/E would install off 4mm DAT tapes, but the layered products, especially DECnet/E wouldn't. Disks on real hardware will be small and slow (an possibly expensive). Well, not neccesarily true. There are SCSI controllers, and large fast disks. But they are often not free. How large disks you can actually use will also depend on what OS you run, with RT-11 being the most limited. What does the availability of disks look like for someone looking to put together a PDP-11 at this point? Unless you're like a lot of us here, and have been doing this for a long time, and built up a supply of spares years ago, such things can be hard to come by. Even Narrow SCSI disks are getting harder to obtain. If you have *ANY* third party controller, you're likely to have a slightly easier time. Any MFM disks will be hard to find, and unlike when I was putting my first system together ESDI disks are likely to be even harder to get. While a SCSI board might set you back a nice chunk of change, it's likely to be the best path. Besides then you can hook up a CD-ROM drive. On emulated systems they can be much bigger and many many times faster. With much more ease, and less cost, yes. Back in the 90's I swore running on real hardware was the way to go. Now, with a nice collection of spare parts, I think Emulation would have been better! Not as fun, but a Linux box running an emulator takes up a lot less space! Thankfully that's the route I went with the PDP-10... Zane -- | Zane H. Healy | UNIX Systems Administrator | | healyzh at aracnet.com | OpenVMS Enthusiast | | | Photographer | +----------------------------------+----------------------------+ | My flickr Photostream | | http://www.flickr.com/photos/33848088 at N03/ |