[Simh] VAX Tape Emulation?

[Zane Healy]

> On Jan 25, 2018, at 6:28 AM, Paul Koning <paulkoning at comcast.net> wrote:
> 
> On Jan 24, 2018, at 8:33 PM, Zane Healy <healyzh at avanthar.com> wrote:
>> 
>> How do I set the tape size to 0?  I’d say that’s a stupid question, but I’ve had very little luck finding documentation on the options.  Though I won’t rule out that I might be blind. :-)
> 
> In the SIMH source tree there's a "doc" subdirectory with documents for SIMH generally, and for each of the ports.  The available configuration commands can be found in the specific port document, for example vax_doc.doc and vax780_doc.doc.
> 
> The commands are defined per controller type, but it looks like the code uses a consistent syntax:
> 
> 	set <unitname> capac=0
> 
>    paul

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/

The v3.9-0 source at Trailing-Edge does as well.
http://simh.trailing-edge.com/

The v3.0 source on the other hand has a vax_doc.txt under the VAX subdirectory.

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

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

Plus it has details on the large disk sizes using SET RQn RAUSER{=n} that I’d found out about last night, and an RRD40 type that I was unaware of.

Next step, installing Linux on a Core i5 box I picked up for $75 recently to run SIMH.  If all this works, it will allow me to *significantly* cut my electricity bill, while keeping my VMS data online and accessible. :-) 

Zane