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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">You don’t need the notion of mountable disk. The disk would appear attached to the guest OS 100% of the time.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">The guest doesn’t need to be able to mount foreign file systems. The guest OS only considers that block device as a seekable collection of blocks. All file movement
between the LIF block device and the OS’s native file system would be by a userland utility.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">True, this utility would have to be developed for every guest OS running under simh, but if the file system was simple enough, the code would be trivial.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">From:</span></b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"> Simh [mailto:simh-bounces@trailing-edge.com]
<b>On Behalf Of </b>skyvis@sky-visions.com<br>
<b>Sent:</b> Wednesday, April 20, 2016 1:04 PM<br>
<b>To:</b> paulkoning@comcast.net; sampsa@mac.com<br>
<b>Cc:</b> simh@trailing-edge.com<br>
<b>Subject:</b> Re: [Simh] Way out idea for simh<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><br>
Just to add some info to the discussion. This sounds like a nice idea,<br>
however it will be very difficult to implement on some of the older<br>
machines that SimH supports. <br>
<br>
For example the B5500 does not have the concept of a mountable pack.<br>
Drives could be attached, but they were a permanent attachment. For the<br>
Ibm 7000 line, most did not support disk. The disk drive that was<br>
supported by many of the machines was a large box that you could not<br>
put drives into (IBM 1301/2301). Also these machines all worked in BCD<br>
(6 bit), not Ascii. I am also not sure when TOPS10 got support for<br>
mounting foreign file systems. I don't believe that 6.03 or 5.03<br>
support this idea. <br>
<br>
<span style="color:#1F497D"><o:p></o:p></span></p>
<p class="MsoNormal">Tapes, paper tapes, and punch cards are probably the most universal<br>
format. Also a Paper tape reader is pretty easy to implement, it might<br>
be possible to put some kind of header onto the tape to indicate the<br>
name of the file. But take a look at how much trouble Kermit does to<br>
handle all the various systems. <br>
<br>
Rich<br>
<br>
------- Original Message -------<br>
On 4/20/2016 12:14 PM Paul Koning wrote:<br>
<br>
<br>
> On Apr 20, 2016, at 12:06 PM, Sampsa Laine wrote:<br>
<br>
> <br>
<br>
> <br>
<br>
>> On 20 Apr 2016, at 19:02, Paul Koning wrote:<br>
<br>
>> <br>
<br>
>>> <br>
<br>
>> <br>
<br>
>> I don't know LIF, but the RT-11 file system is certainly simple.<br>
<br>
>> <br>
<br>
>> There are a couple of complications. First, you'd have to write a file access utility for each guest OS. Given a simple enough file system that isn't necessarily a huge burden. Then again, what might be simple, requiringly only modest code, on one machine
might be a major burden on another simply because it has much less memory.<br>
<br>
>> <br>
<br>
> <br>
<br>
> For DEC stuff, Files-11 (level 2?) would probably work across most of the OSes.<br>
<br>
<br>
<br>
No, it would work for VMS, and level 1 at least would work for RSX, but neither RSTS nor RT11 understand it. And it's a complex file system, more so than the RSTS one and vastly more than RT11. It does more, of course, but if you're looking for something that
can easily be ported to another system, this won't do.<br>
<br>
<br>
<br>
I took the proposal to mean: find a simple OS for which you can easily implement an application to handle it on most operating systems. So think something handled by an application like PDP-10 FLX (or RT-11 FLX), not a file system with native support.<br>
<br>
<br>
<br>
> ...<br>
<br>
>> <br>
<br>
>> Paper tape is yet a third option, which is presumably unlabeled but often transparent. (Not always, the 1620 comes to mind as a notorious example of a machine that could read only coded tape with punches conforming to the code it expects.)<br>
<br>
> <br>
<br>
> That’s a good point but doesn’t make organising files trivial.<br>
<br>
<br>
<br>
One key question is how important it is to transfer a bunch of files all at once. Is it sufficient to send one file at a time? With scripting, that may not be all that problematic.<br>
<br>
<br>
<br>
paul<br>
<br>
<br>
<br>
<br>
<br>
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<br>
==========================================================================<br>
Richard Cornwell<br>
<a href="mailto:skyvis@sky-visions.com">skyvis@sky-visions.com</a><br>
<a href="http://sky-visions.com">http://sky-visions.com</a><br>
========================================================================== <o:p></o:p></p>
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