[Simh] Pdp8 terminals

[Johnny Billquist]

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.

	Johnny

> 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. The
> original DECtape controller for the PDP8 was a single-cycle data break
> device; the later TC01 and TC08 were three-cycle data break devices. The
> original RK controller for the 8/I was very different from the later
> RK8E. In general, peripherals unique to the 8 and 8/I, such as the
> DC08(A), are not implemented.
>
> /Bob
>
> On 9/6/2016 12:00 PM, simh-request at trailing-edge.com wrote:
>> Pdp8 terminals (Gene Irwin)
>
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