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

[Toby Thain]

On 2018-12-11 9:15 AM, Paul Koning wrote:
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>> On Dec 11, 2018, at 7:59 AM, Toby Thain via cctalk <cctalk at classiccmp.org> wrote:
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>> 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 ...
>>
>> 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).
> 
> I made such a setup in college: we had an 11/20 with AA11 (and other lab I/O gear).  I hooked those up to the X/Y inputs of a scope, and a digital I/O line to the Z input.  Then loaded coordinate pairs into a buffer on the RC11 disk, which was set up to do DMA directly to the AA11 data CSR.  Worked nicely, and with low overhead on a  machine that certainly could not afford to do refresh in software.

Curious what year that was, if you don't mind disclosing?

> 
> The classic example of a computer display like that is the CDC 6000 mainframe console.  That is essentially a pair of oversized oscilloscopes (with electrostatic deflection), with their X/Y inputs driven by a dedicated display controller that includes a vector character generator.

Definitely a standout example. And Tektronix vector terminals were also
a whole other category of sophistication.

--Toby

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> 	paul
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