[Simh] TU-56

[Paul Koning]

> On Mar 24, 2016, at 5:55 PM, Mark Pizzolato <Mark at infocomm.com> wrote:
> 
> On Thursday, March 24, 2016 at 2:40 PM, Christian Gauger-Cosgrove wrote:
>> On 24 March 2016 at 18:13, Bill Cunningham <billcun at suddenlink.net> wrote:
>>>    My apologies for posting carlessly and not entering a subject. I
>>> do now indeed have the latest simhvmaster mar 2006. OK. I see vax780
>>> supports TU-50. Will that also support TU-56. Sorry for my ignorance.
>>> Maybe I am overlooking TU-56 support somewhere.
>>> 
>> Neither the "vax780" (VAX-11/780) or "vax8600" (VAX-11/790... sorry, I mean
>> VAX 8600) simulators support the TU56 DECtape, but they do support TU58
>> DECtape II.
> 
> This is not merely a problem with lack of simulation.  The goal of the simh 
> simulators is to simulate what was really supported on the original hardware 
> that is being simulated.  DEC didn't support TU56 DECtape on any VAX system, 
> hence the device isn't included in the VAX simulators...

That depends on the definition of "support".  I know that Andy Goldstein implemented support, even including the famous "overlapped seek" mode familiar from TOPS-10.  I don't know if that code was ever included in a shipping version (presumably as a hidden feature).  I suppose one could ask him, or just try it.

	paul