|
Vintage Test Gear and Workshop Equipment For discussions about vintage test gear and workshop equipment such as coil winders. |
|
Thread Tools |
10th Apr 2019, 5:35 pm | #1 |
Hexode
Join Date: Nov 2006
Location: Biedenkopf, [Hessen], Germany.
Posts: 424
|
Just 4 Fun, the plotter movie
the plotter movie, full HD.
HP scope 54601A + HPIB Option connected to a 7475 Pen Plotter do not watch this with handy when you have to pay for the data, the plotter movie will load around 1 GigaByte. http://www.wellenkino.de/video/54601A_7475A.mp4 greetings Martin
__________________
www.wellenkino.de Vintage Scope restorations |
10th Apr 2019, 6:38 pm | #2 |
Guest
Posts: n/a
|
Re: Just 4 Fun, the plotter movie
I had a plotter years ago, I could (and did) watch it for ages!
|
10th Apr 2019, 6:53 pm | #3 |
Dekatron
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 13,953
|
Re: Just 4 Fun, the plotter movie
Lovely!
I used to support some sites that used loads of HP7475A pen-plotters. They were trusty workhorses but had one fundamental flaw. HP-GL (their plotting 'language') had a number of intrinsic callable functions - like "Draw a circle of radius A using incremental steps of B centred at point [X,Y]" - these functions only took up a few tens of bytes to transmit. The 7475A used a single shared-memory-space model to handle incoming data on its RS232 or IEE-488 [controlled by XON-XOFF or hardware-handshake] and the points generated by its callable-functions. So if you sent it a few bytes of a callable-intrinsic-function command that resulted in it generating a few thousand [X,Y] coordinates, but its shared-memory was already well-stuffed with inbound data.... the results were never elegant. |
11th Apr 2019, 12:07 am | #4 |
Moderator
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 22,803
|
Re: Just 4 Fun, the plotter movie
The scope has a raster display and keeps data that way. The plotter and HPGL are vector oriented. You can really see how the raster to vector conversion is stingy with plotter memory!
These pen plotters were great to play with. Somewhere in a bit box, I think I still have the servo motors from an early prototype grit-wheel drive mechanism. It was code-named "Sweetheart" David
__________________
Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done |
11th Apr 2019, 11:53 am | #5 |
Nonode
Join Date: Jan 2009
Location: Bristol, UK.
Posts: 2,059
|
Re: Just 4 Fun, the plotter movie
Sorry, but it's not right to rasterise that display!
I'm a bit suprised TEK did that ... Many years ago, I used these type of plotters to draft PCB layouts, for subsiquent photo reduction. I'm sure it was using vectors for that. The pens probably cost more than getting a PCB factory to do all that now ! dc |
11th Apr 2019, 8:49 pm | #6 |
Moderator
Join Date: Mar 2012
Location: Fife, Scotland, UK.
Posts: 22,803
|
Re: Just 4 Fun, the plotter movie
Those HP54600 series scopes have a small TV monitor as the CRT.
The incoming voltage is sampled, but the sampling clock has an erratic analogue modulation of the sampling time. A counter and an analogue interpolator measures the trigger to sample timing so the CPU knows where to plant that sample in the memory mapped onto the display. This acts to break up the regularity of sampling artefacts and it gives much better time resolution than you'd expect given the sampling rate. THe disadvantage is that these are downsampling scopes built around Motorola 20MS/s ADCs and so can only handle high frequency waveforms if they are repetitive. THe plotter is 100% a vector driven machine, that's why there is a fudgy interface from the raster format scope. David
__________________
Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done |