[Simh] VAX Tape Emulation?

[Larry Baker]

Clem,

MultiNet included rmt support.  I do not know which versions included it or whether MultiNet has a Hobbyist License.

Larry Baker
US Geological Survey
650-329-5608
baker at usgs.gov



> On 25 Jan 2018, at 7:57:30 AM, simh-request at trailing-edge.com wrote:
> 
> Message: 1
> Date: Thu, 25 Jan 2018 09:57:54 -0500
> From: Clem Cole <clemc at ccc.com <mailto:clemc at ccc.com>>
> To: Zane Healy <healyzh at avanthar.com <mailto:healyzh at avanthar.com>>
> Cc: Mark Pizzolato <Mark at infocomm.com <mailto:Mark at infocomm.com>>, simh <simh at trailing-edge.com <mailto:simh at trailing-edge.com>>
> Subject: Re: [Simh] VAX Tape Emulation?
> Message-ID:
> 	<CAC20D2Ouuwmo_1bO_uUxNPofi7pV5iRRP=qvWujoN4B-sye=VQ at mail.gmail.com <mailto:CAC20D2Ouuwmo_1bO_uUxNPofi7pV5iRRP=qvWujoN4B-sye=VQ at mail.gmail.com>>
> Content-Type: text/plain; charset="utf-8"
> 
> On Wed, Jan 24, 2018 at 5:25 PM, Zane Healy <healyzh at avanthar.com <mailto:healyzh at avanthar.com>> wrote:
> 
>> 
>>  I’d like to backup to a simulated tape drive on the one emulated VAX.
>> The largest drive on my Alpha is 50GB.  I’d prefer not to have to span
>> tapes. :-)
> 
> ​Another thought...  what are you running the emulator on?  Is it a
> UNIX/Linux flavor of some type?   I ask because there might be another
> solution that could work a little better in practice, although you'll need
> to pull together some pieces.      The problem is the bits in my brain WRT
> to VMS are 20+ years old and I've forgotten the details so you'll have to
> do some homework.
> 
> At one point, I remember that some VMS folks in ZK3 (CJ Coppersmith seems
> to stick in my head by I do not remember) were messing we putting a the UCB
> sockets library into VMS and were somebody ported the Berkeley rcmd(3)
> suite on VMS from Tru64.   I'm not sure if how much of that library or
> which commands ever saw the light of day in a production version of VMS.
> But the idea (then) was that a VMS system could use remote services (such
> as a tape) via a socket.  The UNIX command is called rmt(8) (and of course
> mt(8) and IIRC rmt(8) was originally based on the rcmd(3) calls from
> rsh/rcp et al.
> 
> So assuming VMS supports same, using mt(8)/rmt(8) is trival on a UNIX side.
>    But more importantly for you is that on the UNIX side the remote
> 'device' can be a UNIX file as easily as a physical tape if the 'source'
> side knows about using a socket as the output 'device.'.  I've used this
> trick to back up some older systems to modern devices these days (my
> Masscomp box for instance).  The "tape files" are stored on my NAS which
> has redundant physical disks etc...  In fact,  I've even recompiled mt/rmt
> for my Mac at one point and I have it working on *BSD with modern tapes
> (just needed to grab the mtio.h file from BSD).
> -------------- next part --------------
> An HTML attachment was scrubbed...
> URL: <http://mailman.trailing-edge.com/pipermail/simh/attachments/20180125/1de6d487/attachment-0001.html <http://mailman.trailing-edge.com/pipermail/simh/attachments/20180125/1de6d487/attachment-0001.html>>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.trailing-edge.com/pipermail/simh/attachments/20180125/9f59064d/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: smime.p7s
Type: application/pkcs7-signature
Size: 1455 bytes
Desc: not available
URL: <http://mailman.trailing-edge.com/pipermail/simh/attachments/20180125/9f59064d/attachment-0001.bin>