[Simh] Which PDP-11 to choose

[Johnny Billquist]

On 2019-07-01 06:07, Eric Smith wrote:
> On Sun, Jun 30, 2019, 19:37 Clem cole <clemc at ccc.com 
> <mailto:clemc at ccc.com>> wrote:
> 
>     You can use RH70 (massbus controllers) and just use the larger
>     (originally expensive) 19” disks from the early days.
> 
> 
> 14 inch, but who's counting.  :-)

Also, even the largest massbus disks weren't that large. And the RP07, 
being the largest, was not really supported that well on the PDP-11. In 
reality you could only run it on an 11/70, and at roughly half a gig, 
it's rather small today.

MSCP disks have the advantage of being able to be arbitrary size, and 
can be very big, and are supported by all models.

Also, speaking of models, I would usually recommend something with 
22-bit addressing and split I/D space. So no 11/40. 11/70 would be my 
choice for a Unibus machine, and 11/93 for a Qbus.
The slight advantage of an 11/93 is the TOY clock. Otherwise it's the 
same as the 11/73 and 11/83.

11/94 is also an option if you want to pretend Unibus, and it can take a 
little bit more ram than an 11/70.

So, large machine, and then put in 4M of memory (more or less, depending 
on model), a couple of really big MSCP disks, and off you go.

   Johnny

-- 
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