[Unix-jun72] DC-11 quick hack

Warren Toomey wkt at tuhs.org
Wed May 7 20:31:24 AEST 2008

On Tue, May 06, 2008 at 09:04:26PM -1000, Tim Newsham wrote:
> Ok, I had some initial success with a quick and dirty hack.
>   - apply the attached patch to your simh tree and rebuild pdp11
>     and copy it into your tools directory.
>     - maps the TTIX device into the DC11 space
>     - forces the CSR to return the carry-detect bit as always on

As a third alternative, it's obvious that Simh should have a run-time
config to set the carry-detect bit as always on, e.g

	set ttix carrier=on

In fact, from reading the Simh source it looks like we can already modify the
DL11 address, something like:

	set ttix address ???		# I can't deduce the syntax

So we could modify pdp11_dl.c to have a run-time variable uint16 ttix_carrier
which is default 0, but settable to 004.

If someone can point out the syntax to change the Simh ttix addresses from
17774000-17774177 to 17776500-17776677, I'd be very grateful!


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