BIG ol tektronix scope 555 - need it gone - make an offer

[Toby Thain]

On 2018-12-11 1:17 AM, devin davison via cctalk wrote:
> The line about being used with an early computer as a display caught my
> eye. How would it be used as a display, what kind of graphics capability
> would it have? is there an interface for the thing for the pdp 11 or a
> modcomp? Those are the old systems i have on hand that i might be able to
> interface to it.

A scope is at heart an electrostatic CRT with X and Y deflection (and
perhaps Z axis blanking control). Many older systems did have such
displays -- the PDP-1 is a well known example (e.g. see Marc and Lyle's
CHM demo on YT[1]). Imlac PDS-1 is another. And before _digital_
systems, scopes or X-Y displays were a typical output medium for
_analog_ computers.

For digital computers, output is point plotting, vector drawing, and/or
character generation depending on the sophistication (= cost) of the
hardware involved. You'd also need to find or write suitable software :)

Yes, there were interface cards for PDP-11, such as AA11 (dual DACs).

Several manufacturers including Tektronix and HP made dedicated X-Y
displays for computer use. These are smaller than oscilloscopes as
relatively little supporting hardware is required for this function.

If anyone has budget to experiment with this, I know that Sphere[2] in
West Kelowna, BC, has a few X-Y displays still in stock. With some
cleverness it's also possible to modify magnetic deflection CRT's for
vector use[3].

But I hope the Tek 555's can find a good home, they're beautiful
instruments. I suggest posting on the TekScopes mailing list[4].

--Toby

[1] https://www.youtube.com/watch?v=1EWQYAfuMYw
[2] http://www.sphere.bc.ca/
[3] https://www.youtube.com/watch?v=k2O01mNVMN0 ,
https://www.thedefenderproject.com/other-arcade-games/building-a-vector-monitor-from-a-raster-tv/
[4] https://groups.io/g/TekScopes

> 
> Trying to find a good home for it. I just went through the back room and
> found another of a similar design, ill post back with that one too. I was
> not even aware i had two of them, quite odd when you can misplace/ miscount
> something so large.
> 
> On Tue, Dec 11, 2018, 12:57 AM ED SHARPE via cctalk <cctalk at classiccmp.org>
> wrote:
> 
>> so many of these older scopes,are getting scrapped we have a few.. there
>> was one made by tek. for example to be sold with TV broadcast gear we
>> cherish here...gave a few others too.. but they do take up room....early
>> scopes are good to display with early computers... in reality it was needed
>> often as early comp. geAR had bad.  mtf !..
>> ed#....  get one... save one...
>>
>> Sent from AOL Mobile Mail
>>
>> On Monday, December 10, 2018 devin davison via cctalk <lyokoboy0 at gmail.com;
>> cctalk at classiccmp.org> wrote:
>> More of a computer list I know, but I need to clean out and this needs to
>> go soon. Big ol tektronix scope on a cart. Was part of a community
>> workshop, i cleared out all their equipment and have not had the time to
>> repair it. I was planning to go over it and put it to work at my desk, but
>> i decided to get a bigger desk and don't have the space for it. i picked
>> up a hp logic analyzer that fits on the desk, and is more than capable for
>> working on my pdp 11 and other minicomputer stuff.
>>
>> open to offers, come pick it up and its yours.
>>
>> https://i.postimg.cc/NFPC5cDG/scope-555.jpg
>>
>> located in Melbourne FL
>>
>> --Devin D.
>>
>