[Simh] PSI for TOPS-20

[Rich Alderson]

> From: G. <gerry77 at mail.com>
> Date: Thu, 16 Jan 2014 14:01:00 +0100

> On Wed, 15 Jan 2014 23:16:20 -0800, Mark Abene wrote:

>> By chance, does anyone have a tape image of PSI for TOPS-20 v7?  I want to
>> get X.25 connectivity going.  Probably a long shot, but doesn't hurt to ask.

> Both Trailing Edge and Bitsavers have BB-W661A-BM (V1.0 1983) and BB-W661B-BM
> (V1.1 1984) tape images, but they are for TOPS-20 V5.1 so maybe they do not
> work with V7. On the other hand, Autopatch tape 23 (V7 indeed) has references
> to PSI V1.1 so you may just want to give it a try... :)

Given that this question was raised in a SimH context, I have to point out that
SimH only emulates a KS-10 processor, which is limited to TOPS-20 v4.1, and
which does not support the DN20 interface (a PDP-11/40 [or /34?]) which does
DMA via the DTE20 into KL-10 memory.  Looking at the tape on Trailing Edge, it
specifies the DN20, so I think that this is a non-starter.

Someone please point out if I'm wrong about this.

                                                                Rich