The 11/782 are no more asynchronous than any multiprocessor system.
The A in ASMP stands for assymetric. As in, the second processor did not
run any kernel code, but is a slave processor to the primary processor.
It gets scheduled with user-land code to run, but any trapping to the OS
means it interrupts the main processor, who do all the work.
Johnny
On 2016-09-07 18:23, Ray Jewhurst wrote:
I think you are like I am. I would like to see every DEC simulator
possible. Right now I am doing some preliminary research into the
feasibility of a VAX 11/782 which is an asynchronous dual processor
11/780. I will need help because I am not a real experienced coder.
On Sep 6, 2016 8:21 PM, "khandy21yo" <[email protected]
<mailto:[email protected]>> wrote:
Just curious,. Is there any thought about emulating any of the Dec
mate Line? I used to deal with them, mostly as wps8. I don't know
what the hardware differences are, but I saw a large number of Dec
mates and only a few pdp8s. How compatible were they?
Sent from my Galaxy Tab® A
-------- Original message --------
From: Ethan Dicks <[email protected]
<mailto:[email protected]>>
Date: 9/6/16 5:00 PM (GMT-07:00)
To: [email protected] <mailto:[email protected]>
Subject: Re: [Simh] Pdp8 terminals
On Tue, Sep 6, 2016 at 1:03 PM, Johnny Billquist <[email protected]
<mailto:[email protected]>> wrote:
> Hi.
>
> On 2016-09-06 18:55, Bob Supnik wrote:
>>
>> The PDP8 simulator is more or less a PDP8/A, and its terminal
>> "multiplexor" is a KL8-JA, which implements four discrete KL8A style
>> interfaces. These are superset compatible with the PDP8/I's PT08
>> discrete interfaces, and thus TSS/8 will work. Note that TSS/8
supports
>> only four discrete terminal interfaces. To get more than four
lines, the
>> configuration must have a DC08(A), a multiplexor for the PDP8/I. The
>> DC08(A) is not implemented at the moment.
>
>
> This can't be correct.
>
> The KL8JA is a single line interface, compatible with the KL8E,
but using
> different hardware. You can add lots of KL8E or KL8JA interfaces
to a PDP8,
> if you wanted to. Each have a different device code, and that's
all there is
> to it. (Talking about the actual hardware here.) In addition, as
far as I am
> aware, the programming of these interfaces are pretty much the
same as the
> console interface on all other PDP-8 models as well.
>
> The KL8A was a very late device for Omnibus, which require a hex
wide box.
> It is a 4 line multiplexor, but the programming interface is
nothing like
> the KL8JA or KL8E. In addition, not all lines are the same. And
again, you
> can add several of these multiplexers to a machine, if you want to.
Agreed... here are the handle numbers to help clarify what we are all
talking about...
M8319 KL8A PDP-8/A 4 channel serial I/O
M8650 KL8E Asynchronous Data Control (current loop or RS232)
M8655 KL8JA Terminal Control (UART based substitute for M8650)
The KL8E and KL8JA are, AFAIK, not easy (or not possible?) to tell
apart in software. The KL8A is entirely different - the only time
I've ever used my KL8A was with RTS-8. I'm not sure I have any OS/8
code that knows how to talk to it. If it's out there, I'd love to
read it.
>> There was a significant evolution in the PDP8 family's IO controllers
>> from the original 8 and 8/I to the Omnibus-based 8/E and 8/A.
Very true. I have a bunch of the real hardware spanning the entire
era and, yeah, Omnibus devices and pre-Omnibus devices are commonly
different (I think the console 03/04 interface is, up to the DECmate
era, the most compatible across the spectrum).
-ethan
_______________________________________________
Simh mailing list
[email protected] <mailto:[email protected]>
http://mailman.trailing-edge.com/mailman/listinfo/simh
<http://mailman.trailing-edge.com/mailman/listinfo/simh>
_______________________________________________
Simh mailing list
[email protected] <mailto:[email protected]>
http://mailman.trailing-edge.com/mailman/listinfo/simh
<http://mailman.trailing-edge.com/mailman/listinfo/simh>
_______________________________________________
Simh mailing list
[email protected]
http://mailman.trailing-edge.com/mailman/listinfo/simh
_______________________________________________
Simh mailing list
[email protected]
http://mailman.trailing-edge.com/mailman/listinfo/simh
