[Simh] 8" Floppy disk image getting HALT error

[Johnny Billquist]

Walker, the commands Tim show are for if you are running VMS. You can 
run VMS under simh, using the VAX simulation.
Then you could connect the images to that running instance, and access 
the floppies using those commands.

However, I strongly suspect that wont be much of a help. From what 
you've described so far, it does not sound like there is any "normal" 
file system on the floppies, but just the text document straight out.
As such, no OS will help you much. You can just read the document out 
from the dump you have. If you have an OS, it can read the disk giving 
you the disk blocks again, but in the end it will be the same blocks you 
already have in the original dump. No further interpretation will 
happen, so it would just be an extra step in order to get the disk 
blocks inside the OS you might be running. But then you probably want to 
get those disk blocks out again, so than you're back to what you already 
have.

I would just grab the disk image you have, open it in some sensible 
editor, and just cut the parts out that is not a part of the document, 
and that's about it.

But then again, this is all based on how I have understood what you have 
described, and there might be bits I'm missing.

	Johnny

On 2017-07-25 18:19, Walker Sampson wrote:
> Hi everyone,
>
>
>
> Thanks again for the help, this has been great. I’ve had a chance to
> loop back to this.
>
>
>
> Tim, I’m not familiar with the VMS commands you’re referring to. Is this
> a virtual machine I can run – something like OpenVMS? I’m unclear on how
> to best access the content on the disk image as a file, given that it’s
> not a bootable disk the SIMH VMs can run.
>
>
>
> Best,
>
>
>
> Walker
>
>
>
>
>
> *From: *Simh <simh-bounces at trailing-edge.com> on behalf of Kevin Handy
> <khandy21yo at gmail.com>
> *Date: *Friday, July 14, 2017 at 3:21 PM
> *To: *Johnny Billquist <bqt at softjar.se>
> *Cc: *"simh at trailing-edge.com" <simh at trailing-edge.com>
> *Subject: *Re: [Simh] 8" Floppy disk image getting HALT error
>
>
>
> Just did a little research on WPS-8 floppy format, just to satisfy my
> curiosity.
>
> WPS-8 stores data on an RX-50 as a series of 12-bit words, using two
> bytes on the floppy to store a word. The low 8 bits goes into the 1st
> byte, and the upper 4 go into the second btype.  4 bits in the secnd
> byte are unused.
>
> It stores two 6-bit characters in each word. To convert it to asCII,
> mask off the 6 bits and add 31. Character 63 (ASCII 94) is a command
> character, and following character(s) specify the command. Some other
> characters are also special '[' and ']'  toggle upper/lower case.
>
> Looking at a WPS-8 floppy in raw mode on a PC would not display anything
> readable, so this guys floppy is obviously not wps-8,and if all pdp-8s
> systems handled floppies the same way (as 12 bit words), it probabl
> isn't from any psp-8.
>
>
>
>
>
> On Wed, Jul 12, 2017 at 4:33 AM, Johnny Billquist <bqt at softjar.se
> <mailto:bqt at softjar.se>> wrote:
>
>     On 2017-07-12 02:04, Timothe Litt wrote:
>
>         On 11-Jul-17 18:02, Johnny Billquist wrote:
>
>             On 2017-07-11 21:09, Timothe Litt wrote:
>
>                 VMS mount /over=id /foreign is the quickest way to
>                 identify files-11 and
>                 RT disks.  FILES-11 can be read directly; use EXCHANGE
>                 for RT-11.  Once
>                 you have the disk mounted on VMS, you can network it to
>                 wherever you
>                 like.
>
>
>             Similar story if you have RSX. I might have forgotten a
>             thing or two
>             about VMS here, but I would have thought /OVER=ID/FOREIGN
>             would not
>             then let you access the disk in the direct way if it is
>             Files-11.
>
>         I was suggesting the easiest way to IDENTIFY the media.
>         /FOREIGN will
>         dump the filesystem type when it looks for a HOM block.  Once
>         you know
>         that, you use the appropriate command / utility to access that type.
>
>         To access FILES-11 on VMS, you don't use /FOREIGN, just mount
>         (though
>         /over=id will allow a private mount without knowing the volume
>         label.)
>
>
>     Ok. Fair enough. I thought you meant that you'd mount it that way,
>     and then go at it.
>
>         MOUNT and EXCHANGE details are available from HELP and the manuals.
>
>         VMS has, arguably, the most filesystem support and tools for
>         this.  But
>         OS choice is a religion.  Use whatever you believe in & have
>         available;
>         there is no point in arguing religion.
>
>
>     True. And, as with any religion, there is no point of even having an
>     argument. Whatever works is good enough.
>
>         Of course, if the OP is more interested in the result than the
>         process,
>         he can probably get one of us to extract the one file for him...
>
>
>     Also true. I'm sure plenty of people would help, if asked.
>
>
>
>             Johnny
>
>     --
>     Johnny Billquist                  || "I'm on a bus
>                                       ||  on a psychedelic trip
>     email: bqt at softjar.se <mailto:bqt at softjar.se>             ||
>     Reading murder books
>     pdp is alive!                     ||  tryin' to stay hip" - B. Idol
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>
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-- 
Johnny Billquist                  || "I'm on a bus
                                   ||  on a psychedelic trip
email: bqt at softjar.se             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol