On 2018-12-11 9:15 AM, Paul Koning wrote: > > >> On Dec 11, 2018, at 7:59 AM, Toby Thain via cctalk <cctalk@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? > > 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 > > paul > > >
