[HECnet] Simplest PDP-11

[Johnny Billquist]

On 2019-02-03 22:42, Brian Hechinger wrote:
> On Sun, Feb 3, 2019, 16:15 Johnny Billquist <bqt at softjar.se 
> <mailto:bqt at softjar.se> wrote:
> 
>     On 2019-02-03 22:02, Brian Hechinger wrote:
>      > What is the simplest PDP-11 CPU/peripheral design that is capable of
>      > running RSX-11, RSTS/E or BSD?
> 
>     Define "simple" please. :-)
> 
> 
> The easiest to implement with limited tools.

If the size of the device driver is anything to go on, then roughly 
ranked from easiest:
RK11
TC11
RP11
RL11

Massbus in general I think can be done to work without too much 
complexity. RK611 shouldn't be too bad, but do add a bit more stuff.

But I think pretty much anything except MSCP is roughly similar in 
complexity for someone implementing it.

   Johnny

> 
>      > Also, what is the minimum disk space needed to install those
>     operating
>      > systems? I have a plan. Probably not a good one but I'll likely
>     learn a
>      > lot in the the process so it won't be a waste of time.
> 
>     RSX-11M-PLUS can run from two RL02, if you just accept the pregen
>     system. But that's the smallest. If you want to build stuff, something
>     like an RK07 is required, and that is 28 Megs. But I think it's
>     recommended that you have two. But that probably is for more reasons
>     than just running the actual system (it is hard to do an update if you
>     are running on an RK07, and the update media is an RK07).
> 
>     RSX-11M definitely gets away with less. RSTS/E would be similar, I
>     think, while BSD probably wants a little more.
> 
> 
> Ok, that's what I needed to know (more ballpark than anything else is fine)
> 
> Thanks!!
> 
> -brian


-- 
Johnny Billquist                  || "I'm on a bus
                                   ||  on a psychedelic trip
email: bqt at softjar.se             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol