On Thu, Jan 23, 2014 at 5:50 PM, William Donzelli <wdonzelli at gmail.com> wrote: I do not need another RK05J, but I will take a stab at your question... It's entirely dependent on your desired OS. I don't know how far back one might go to find a suitably small RSTS version that fits in 2.5MB, but many (most?) versions of RT-11 will fit in that much space, and compared to a floppy install, an RK05-based RT-11 system will feel quite zippy. In the 1980s, we ran multi-user RSTS and RSX-11/M systems on a single RL02 and in the same timeframe, I was running RT-11 on a single RL01 with lots of free space. It might be a "waste" of the resources of an 11/45 to run RT-11, but it will surely work. If you have decided on what OS you would like to run on the 11/45, see if you can find the SPD for it. That flyer will contain, among many other facts, the minimally-supported disk configuration. You can often squeeze things tighter than the SPD indicates (trimming libraries, help files, less-common-used utilities, etc), but it's likely that a vanilla install would fail if you try to undersize the recommendations. If I wanted to run a box with a single RK05, I'd also want removable media, something other than the boot disk: RX floppies, TU58 tapes... something, real or emulated, just to be able to migrate programs and data on/off the machine. With enough RAM to run vtserver, it's not as critical - you can keep RK05 images on a modern machine and dump/blow your images from/to the same pack over and over. -ethan

Hi William, I worked on what was supposed to be the longest unibus on record- it had 2 DB11 bus repeaters in it. I don't remember what OS it used, but I'm sure RT11 would run fine on a standard 11/45. On a side note, A TU10 is one or the few DEC things I'm looking for yet. On Thu, Jan 23, 2014 at 4:50 PM, William Donzelli <wdonzelli at gmail.com>wrote: