[cctalk] Re: oscilloscopes

Ignore my last - incontinence or is it incompetence A fairly ordinary GPU, in a PC, could almost certainly provide an XY display with Z fade (long persistance phosphor). I use them for waterfall displays and they keep up - the data does of course arrive by E'net. Equally, FPGAs / SOCs can implement frame buffers; eg to output waterfall displays. The fading memory would have to be in DRAM, FPGA memory is fast but small 3 ns access time but only 240 ki by .. 2.18 Mi by (Zynq 10 .. 45, the '45 is a corporate purchase). A ping pong buffer arrangement could implement fading - computed in either processor (vector instructions) or logic (raw muscle). The DAC input lines could supply the data. Martin -----Original Message----- From: Guy Fedorkow via cctalk [mailto:cctalk@classiccmp.org] Sent: 03 April 2024 16:02 To: cctalk(a)classiccmp.org Cc: Guy Fedorkow &lt;fedorkow(a)mit.edu&gt; Subject: [cctalk] Re: oscilloscopes Vintage computer enthusiasts might want to keep track of where to find CRT-based analog oscilloscopes, for use as output devices. The early MIT and Lincoln Labs computers used D/A converters to steer and activate the beam on analog scopes to draw vector images. Working on Whirlwind simulation, we've been able to get this technique to work with "real" oscilloscopes, e.g., Tek 475, but we have not yet found a single DSO that has X/Y _and_ Z inputs (let alone the required phosphor fade).   Myself, I have a couple scopes with backups, so I'm not in the market for another one.  But others might consider the option...   /guy fedorkow Date: Mon, 01 Apr 2024 22:33:38 +0000 From: Just Kant&lt;kantexplain(a)protonmail.com&gt; Subject: [cctalk] oscilloscopes To: "General Discussion: On-Topic and Off-Topic Posts" &lt;cctalk(a)classiccmp.org&gt; Message-ID: <xVKPUUPAeHv0_Gdsaq0al3Lji6a5VLAX2wRSUo5YhZwiADr5zn171nRBM NxX-XE1ru7jPj1GFbu0aE3uBwUsVKxlU_XAYKX9B0x42zJZADc=(a)protonmail.com&gt; Content-Type: text/plain; charset=utf-8 I have more then I need. All the working ones are HP w/color crts, and as far as older, verifiably vintage tools (right down to the 680x0 processor in either) I have to admit I favor them as a brand. Call we an oddball, weird egg, badges I wear with pride. But who could resist the allure of the newer ultra portable, even handheld units (some with bandwidth or sampling rates to 50mhz). I'm a big cheapo. But there's no real reason to agonize over a 65 - 200$ or thereabouts acquisition. It's a bit tiring to wade through the piles of availability. I favor a desktop unit, larger screen (but not always, careful). But most of those need wall current I think? The convenience of a handheld battery powered unit obviously has it's benefits. I will always love and dote upon my color crt based HPs. But the damned things are so heavy, so unwieldy. Judy-Jude knocked my 54111d over, hit the paved floor, shook the house. And still works! Built to withstand an atomic bombardment.