[GreenKeys] Fw: Building a KSR using today's technology?

[Keith Mc]

On Jul 11, 2012, Jeffrey D Angus <jdangus at att.net> wrote: 
> Ah yes, what we used to call the "Sneaker Net"
> 
> You grab a hand full of tapes and pull your sneakers on and
> walk over to the other machine.

Actually, it was MUCH better than Sneaker Net, as
I did it all from my ASR33 (& Televideo and later a DEC VT100
CRT) "at home" over a phone line.  No running around needed AT ALL!

At that time I was in my early 20's living in a mobile home 
park to save up money for my first house.  I had the ASR-33 
in my "den", a hallway off of my kitchen, made by tearing 
out a couple of non-load bearing walls off the back bedroom... <grin> 

I simply sat there, dialed up one machine, and printed it, 
while punching paper tape or recording the modem tones 
onto audio cassettes via the suction cup pickup coil stuck 
onto the earpiece of my ATT desk phone's handset.    

Oh yea... I forgot.  When I moved up to 300 baud
at first I was ecstatic...  Close to 3x speed improvement!

But then I discovered I had a NEW problem...  I could 
play back the tape to my CRT by flipping the modem tones.  
But, I could not read them back in to another computer,
because the modem was busy decoding tapes, and 
was not available for tying to the phone line!  <DOH!>

Not a problem if I had the forethought to record it at 
110 baud.  I could then cut a paper tape, then switch things 
around again so I could again use the modem for the 
phone line, then play the Paper Tape back in to the new 
computer with my ASR33.

But otherwise, I had to transcribe from the CRT,
punch a tape, and read that in.  That got pretty old
darn fast, AND defeated half of the point of the whole rig...

To solve THAT one, I had to hack an RS232 connection 
between TWO modems.  That allowed me to use the 
acoustic modem with flipped settings to decode the 
audio tape back into RS232 signals.   

The wires then ran to the SECOND modem with a hacked
transistor logical "OR" connection interface.  This combined 
the audio data stream with data from my CRT, such that 
if EITHER went to Space, it sent a character of data.   

This allowed me to use both the tape AND the CRT together.  

This was necessary, because I needed to often type in 
a single CTRL-Z to close off the file once read in.   
Some systems needed that one lousy character to
allow me to close the file, or simply close off the 
Insert mode and get to the SAVE menu to finish 
the edit-insert job.  Otherwise, I'd be REALLY close to 
being done, but then have to forfeit the entire job because 
I couldn't properly close the edit session.

BTW... I often intended to make a simple "CTRL-Z" 
"CTRL-D" and "ESCAPE" one-character state-machine 
"generator circuits" to get around that problem, 
but the wired-or interface was easier to make.

It was also a more general purpose solution, as
I could then type ANY character the editor needed,
(including the Save file name, CR, etc...).

One workaround I came up with was to make an audio 
tape with the data I needed on it typed in from the 
CRT or ASR33, and "edit" the two tapes together 
physically, with a cassette tape splicing block...  
You may get a bobble character or two, but that 
can be worked around.  But that was VERY messy.

The Wired-OR interface solved a lot of problems.

BTW... In addition, the second modem moved from 1200, 
up to 19.2K and beyond as the new tech became available.  
This extended my entire system for additional years
because computers weren't recognizing dial-ups
below 1200 baud any more..

Eventually though, the ASR33 had to be retired,
then the entire rig.  Many of the systems eventually 
had a lower limit of 300 or 1200 baud on their modem links.

Once the lower speeds were no longer supported, 
that was that.  The new modems couldn't flip orig/ans mode
as easily.  

In addition, the audio recordings didn't work well with 
the faster modem tech, because the tech involves a 
"negotiated bandwidth handshake" between the two
modems, which a dumb tape recording can't support.

> Or the other comment, "Bandwidth? You can't beat a
> station wagon full of tapes."

Actually, in the heyday of that, I actually had four rows
of four drawer stackable cassette tape organizers on
a shelf, for my audio tape collection.  That gave me 
storage for something like 300-400 C-90 audio cassettes.
(You could buy 10-packs of C-90s pretty cheaply back then. :-)

To be fair, MANY of those tapes were actually used for
AUDIO recording.

But... I'll leave it as an exercise to the readers to estimate
how many "theoretical" characters of storage that shelf 
COULD have represented. (Assume: 400 C-90s, ~85% 
utilization to account for end of tape and space between
files, at 300 baud :-)   

That was my physically large, low density, "backup jukebox",
that served my data storage and inter-machine file transfer 
needs for almost a full decade with my ASR33 and CRTs... <grin>

Once CP/M and PCs came along, I shifted the entire system 
over to higher speed modems and storage on floppies, 
but I still did a lot of the same rituals with editors on the 
uploading machine.

Once the internet happened, it all went to inter-machine FTP.
What a breakthrough!

Today, email, HTTP, online drop archives, and cloud 
resources supersedes it all...

- Keith Mc.
"Seamless cloud computing?  It often appears more like a 'fog' at times..."