[Simh] VAX-T and PDP-11-T

[Villy Madsen]

The DN-11 had no communications capability - it was an autodialer 
controller pure and simple. Any communications that took place was through 
a standard ASYNC comm port which was connected to a modem which was 
connected to an autodialer - which was connected to a phone line and also 
to the DN-11.

Actually any IO device could be used since all the DN-11 connection is used 
for is to provide an IO memory address - it doesn't even function as a 
device.

and of course once autodialing modems became available - the need for the 
DN-11 disappeared.  I don't know about others' experience, but our 
autodialers (not the DN) burned up with amazing regularity (we used them 
for dialing voice lines, the operators loved that feature !!))

Villy

On Tuesday, May 23, 2006 04:10, Kevin Brunt [SMTP:k.brunt at ccs.bbk.ac.uk] 
wrote:
>
> Hi.
>
> I'd like to make one small point about the use of the DN-11 for this.
>
> UNIX V6 and V7 on the PDP-11 supported the DN-11 for UUCP. (UNIX did come 
from
> a telephone company, after all.) Compared to the existing code base, 
there is
> relatively little additional work needed to extend the DL-11 support and 
add a
> DN-11 based outgoing TCP connect operation, and so create a SIMH UUCP
> networking capability.
>
> It would be a shame if the Throttle support conflicted.
>
> Kevin Brunt
>
> On Mon, 22 May 2006 20:33:42 -0600 Villy Madsen <Villy.Madsen at shaw.ca> 
wrote:
>
> > The distributions on
> >
> > http://68.150.97.212/simh/
> >
> > have been updated
> >
> > The new files are called pdp11-t-001.zip and vax-t-001.zip
> > Throttlev2.zip replaces all previous versions of throttle
> >
> > Changes
> >   The DN-11 driver has been changed to set the performance control
> > variable to zero (full throttle) when a device reset occurs.  This 
happens
> > when the simulator starts to boot the cpu and during the VMS boot 
cycle.
> >  The only effect that this has is when a shutdown reboot is requested, 
and
> > the CPU has not been throttled up prior to the shutdown completing.
> >
> > The VAX and PDP-11 simulator names have been changed to:
> >
> > VAX-T-001  (T for throttled and 001 for the version number).
> >
> > Ther version number for THROTTLE has been reset to V2.  RESETTHROTTLE 
and
> > READTHROTTLE have been deleted from the distribution.  The throttle 
program
> > now reads a system logical to set the minimum throttle value and writes 
a
> > system value to indicate the current throttle value being used.  The 
min
> > value is read every program iteration (2 seconds) and the current value 
is
> > written every iteration.
> >
> > It seems solid..  Problem reports, comments and change suggestions to:
> >
> > Villy Madsen
> > www.members.shaw.ca/villy.madsen
> >
> >
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>