On Sat, Dec 12, 2015, Jon Elson wrote (in the big top posting thread):
> On 12/12/2015 07:22 AM, Mike wrote:
> >The one question I do have for the older gentlemen on here is what in the
> >world did the computers without a screen to look at do? Now I know about
> >the tape, cassette tape's and even the paper with the hole punches in them
> >but what kind of applications were they use for? Mathematics or? ? ?
[snip]
> Later they got some
> IBM 2260's, which were Zenith 9" TV sets and a keyboard connected to an
> interface box in the machine room. Very primitive, but very interactive,
> great for quick program editing and submission.
I'm reading about those terminals and find it just fascinating how they
used acoustic delay line memory to remember the pixels. But I have lots
of questions:
1. Did the cables connecting the 2260s to the display controller
actually contain the delay lines themselves, over the whole length; or
were the delay lines just inside the controller and then some electronic
signal was sent out to the terminals?
2. I would think that the wave travelling along the delay line would
weaken over time. How was it refreshed?
3. What kind of speed could be acheived, and did this depend on the
number of connected terminals?
--
Eric Christopherson
I have what was once an IBM 2970 Reservation Terminal. Some time in
the late 1970s. an outfit called 'Western I/O' got hold of a bunch of
these, including mine, ripped out all the IBM electronic guts (but
left their electromechanical bits - solenoids and contacts) and
installed their own boards, and sold them to the home-brew computer
folks of that day - presumably hung off contemporary Altair and Imsai
machines etc.
They made two versions. One was a fancy full-blown terminal with a
6800 microprocessor, adjustable baud rates, standard RS232 port etc.
I'd really like to get hold of one of these if anyone has one
gathering dust btw...
The other one was a very dumb print-only versions. According to
contemporary ads, it has:
"? Printer-only model availability w/parallel ASCII interface."
"The Printer Terminal
IBM Selectrics are known for their well-defined,
high-quality printed characters and easy-to-
change elements. An ideal choice for text
processing, highly-legible source listings and
personal or business correspondence. And it's
easy to connect to home or business computer.
Just plug in 115 Vac, hook up the ASCII printer
port and let 'ergo."
That is ALL the documentation I have on this thing!
The 'parallel ASCII interface' is implemented as a DB25 female on the
rear of the Selectric. It *looks* exactly like a parallel port on a
PC. So I hoped it would use standard parallel port pinouts and a
straight-through ribbon cable would do it. No such luck.
I don't have a parallel port analyzer, but I have lots of serial port
analyzers, including ones with an LED per line, all 25 lines. So that
is an improvised window into what's happening. For starters. when I
operate the 'paper out' switch, I can see a line going high/low
corresponding to switch position - but it's pin 19 on the DB25
connector, which should be ground on a standard parallel port! 'Paper
out' should be on pin 12. So it's clearly not standard...
Now I can start tracing pins on the interface back to lines on the
PCBs, and try to figure what they do. At least I can relatively
quickly eliminate those that aren't used, or are ground plane.
But, question: back in the day, was there *another* 'standard' for
parallel port pinouts? Used on S100 bus PIO etc. cards, the kind of
thing this product was intended to be used with? I've found Googling
on such data to be remarkably unproductive... any help out there?
Mike
> Sometime later, maybe around 1971 they got some IBM 2741 terminals which
> were Selectric typewriters connected to an interface. Later they got some
> IBM 2260's, which were Zenith 9" TV sets and a keyboard connected to an
> interface box in the machine room. Very primitive, but very interactive,
> great for quick program editing and submission.
Were 2260s really Zenith products inside? I certainly could believe
it, judging from the tube lineup. Someday I would like to see one up
close and personal.
The 1800 actually did have a video option, and yes, you had to provide
your own cheap black and white TV.
--
Will
>
> I'm not sure I understand what all this posting business is about.
> The application (Thunderbird) puts the text where it wants.
> In my case at the top. ie LIFO or latest first. It does the same with
> the list of messages
>
> Decmail did this from its inception as did the IBM, HP. etc mail systems.
> I can't understand what the fuss is about. Please explain
>
The explaination in the signature in some of David Griffith's postings is about
the best and most succinct I've seen.
Regards,
Peter Coghlan.
Since I've fallen _way_ behind in reading my email (I'm reading July 2015's
messages now), I've just recently read a thread where removing the
batteries from VAX 4000-xxx systems was discussed and recommended.
Since I didn't get _any_ documentation when I rescued my VAX 4000-200
system, which module(s) contain batteries that I should remove for safety?
Or can you recommend the appropriate manual(s) at sites like Bitsavers that
I download & study to locate to the batteries to remove before they leak
and cause corrosion issues?
Hopefully I don't already have a big mess to clean up!
Thanks,
Bob
So I know someone who has a working 11/34 (4 RLO2's and the 11/34 in an H960,
running RSTS/E) they want to sell, and they want to know how to maximize the
value - i.e. whether to sell it as a complete working system, or to part it
out - and if the latter, how to break it up?
(No discussion about the morality of parting it out, please; this is owned by
a business, and they need the money to pay people's salaries.)
So which direction would get the most money? My sense is that parting it to
the maximal degree possible (e.g. sell each drive separately, sell the memory
separately from the CPU, sell the feet separately from the H960, etc) is
the way to get the most money, but I'm interested to hear what others think.
Thanks for any insights!
Noel
> From: Pontus Pihlgren
> Once, I was told by a friend that he had dumpstered not one but two
> PDP-12s!!
> It still gives me the chills.
I can top that. Someone told me they were going to start a thread about
top-posting on a list supposedly about vintage computers. I'm still
shaking.
Noel
I was searching Craigslist and found this post with 7 boxes of C64 stuff
One C64 was still in the box, hard to find games great books and much
much more here is a link to what I got! once I have it all setup Ill
upload some more pictures.
Here is a link to the photos...
http://s1093.photobucket.com/user/mikesatcshop/library/Commodore%2064
My wife is using my table that I am going to use to set it all up so as
soon as she is done I will set it all up so you guys can see it all then
I am sure I will have a few questions for the group.
Are there any other Commodore 64 users out there?
I hope I can meet lots of other people that have a love for vintage
computers as I do.
