[Simh] transferring files to and from v6 unix running in pdp11 emulator

[Will Senn]

On 11/20/15 4:07 PM, Rich Alderson wrote:
>> From: Will Senn <will.senn at gmail.com>
>> Date: Fri, 20 Nov 2015 10:35:06 -0600
>> How can I efficiently copy files from my host system to unix version 6
>> running in the pdp11 emulator and from unix 6 to my host system?
> You have gotten a number of answers, but none of them strikes me as the
> best method for what you want to do.
>
> There is a raw 8-bit device (well, pair of devices) on the PDP-11 which
> will do the trick:  The paper tape reader/punch.  Simply cat the file onto
> a paper tape image, or cat it from a paper tape image into a file.  Won't
> care whether it's text or binary.  Won't revise the content to match a
> display (\t will stay \t).
>
> I've used this in the past.  It works.
>
>                                                                  Rich
> _______________________________________________
>
Rich,

This looks like the easiest method for text so far. However, I am 
getting interesting results that I hope ring a bell for you or someone 
else listening in...

I edit a text file on the host
vi ptr.txt
Hello World

fire up the simulator and:
simh> attach ptr ptr.txt
simh> attach ptp ptp.txt
co

# cat > hello < /dev/ppt
# cat hello
Hello World

Yee ha, I can read from paper tape.

cat hello >  /dev/ppt

Bummer, nothing is written to ptp.txt. Well, as it turns out, the data 
is sent to the tape, but it doesn't appear in the file until I suspend 
the simulation with CTRL-E.

I tried sync's and waiting and no go. CTRL-E, immediately writes the 
file. Does this sound like expected behavior or perhaps a bug?

It still works, mind you. I don't really mind suspending the instance 
after a sync or two, but it isn't ideal.

Thanks,

Will