OS/8 Disk Server Release

On Sun, Feb 9, 2014 at 8:57 PM, Kyle Owen <kylevowen at gmail.com> wrote: Very cool. Awesome. The one I know about is BSW. It doesn't swap the upper and lower 6 bits in the AC on pre-OMNIBUS machines. Some of the more "interesting" single-instruction-AC-load microprogrammed IOTs depend on it. I was looking around for a list of which instructions are specific to which models of CPU since part of that is how the CPU detection in FOCAL works. I know it's documented somewhere, but a search of a few minutes did not turn up specific information, just general discussion that there are differences. Since OS/8 requires 8K minimum, it's probably reasonable to consider supporting the PDP-8/L and PDP-8/i but not to get too worked up about supporting older models. If it can be done, sure, there's no reason not to, but if there just aren't enough locations to bum for all models, but there is for the PDP-8/i and newer, I'd say that's probably an adequate target. There just aren't that many systems from the mid-1960s that have enough RAM to run OS/8. Personally, one of my long-term goals is to either upgrade my 4K PDP-8/i to 8K (or more!) or to find a mass storage device for my 12K PDP-8/L so I can run OS/8. It's not impossible to add an extra serial port to the -8/L, so the os8diskserver might be an easy way to do it. I have a several DF32s, but they are all Negibus (not DF32D) and I don't have a Negibus-Posibus converter (DW08?) Some day, I *will* have OS/8 running on a 1968-era machine! I _think_ the RK05 does a seamless seek across sides. I'm far more experienced with the RL8A and RL01, but I think I remember a note saying the RL8A was *not* like the RK8E/RK05 because it _did_ require an explicit seek across the boundary. -ethan