[Simh] VAX Tape Emulation?

[Paul Koning]

> On Jan 25, 2018, at 10:50 AM, Zane Healy <healyzh at avanthar.com> wrote:
> 
> 
>> ...
> 
> Interesting.  I wonder if the documentation has gotten dropped somehow.  Either that or I’m still being blind.
> 
> As far as I can tell, the GITHUB repository lacks such files.
> https://github.com/simh/simh/tree/master/

No, it's right there.  Remember that Github displays are case sensitive, so all the machine directories (being upper case, apart from "alpha") come first, then the lowercase ones such as "doc".  

> ...
> I’m using the SIMH build on Ubuntu in a VM.  That appears to be v3.8-1, and oddly enough you can do “man vax” which points you to where the doc’s are.  Here are some of the applicable looking ones.
> -rw-r--r-- 1 root root  34768 Mar  2  2007 simh_magtape.pdf
> -rw-r--r-- 1 root root 188726 Feb  8  2009 simh.pdf
> -rw-r--r-- 1 root root   3501 May 27  2008 vax780_bug_history.txt
> -rw-r--r-- 1 root root 107942 Feb  8  2009 vax780_doc.pdf
> -rw-r--r-- 1 root root 117234 Feb  8  2009 vax_doc.pdf
> 
> And there is the info I was after, in vax_doc.pdf. :-)
> 
> SET TS0 CAPAC=m

Then again, 3.8.1 is quite old.

> It looks like the TK50 emulation is limited to 2GB, so I don’t want to use that.

That's rather confusing.  There's a controller setting that specifies the device type (which doesn't make much sense since device type is a unit property).  But there is still a unit capacity command that seems to override the device setting.

> Plus it has details on the large disk sizes using SET RQn RAUSER{=n} that I’d found out about last night,

Yes, RAUSER is nice to make up virtual disks of arbitrary convenient size.

	paul