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

[Paul Koning]

> On Dec 11, 2018, at 3:30 PM, Toby Thain <toby at telegraphics.com.au> wrote:
> 
> On 2018-12-11 9:15 AM, Paul Koning wrote:
>> 
>> 
>>> On Dec 11, 2018, at 7:59 AM, Toby Thain via cctalk <cctalk at classiccmp.org> wrote:
>>> 
>>> 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?

1974, at Lawrence University which had that 11/20 (with 8 kW of memory, DECtape, RC11, AA11, AD01, DR11, and ASR33) in the physics lab.

	paul