[Simh] FKABD0 diagnostics 11/34 fail in simh?

[Shoppa, Tim]

Al writes:
> Brad Parker wrote:
>> pretty obscure, I know, but I'm doing co-simulation and looking for 100%. 

> There is a table of all of the implementation variations in the back of the later
> PDP-11 manuals. It's certainly possible that Bob missed some corner cases of a
> particular architecture.

That table is useful, but sometimes incorrect, and certainly not complete.
At least not complete enough to be sure that every diagnostic (written knowing
The gate-to-gate wiring in each different model) will get what it expects.
In some cases not complete enough to actually get the OS's to run.

The diagnostics are an interesting set of tools. Usually they go far beyond
Simply checking for conformance to the published architecture.
The older diagnostics were written to help do board repair to the component level.
Some are exercisers designed to trigger specific patterns for the logic analyzers of the day.
And often check all sorts of corner cases unknown to anyone except the
Diagnostic author :-).

Some emulator writers have the goal of passing every original diagnostic; a
More realistic goal is often to implement the published architecture and then
Run the OS's and utilities and applications.

Tim.