Hi guys I was wondering if there was a way to hack into the number of lines. For examples having 256 horizontal lines or 4. Maybe there is a way by triggering differently the vertical ramps? With a frequency divider or something like that… Any idea? I would like to try.
You seem to be asking “can I change the number of scanlines on a TV?” Yes, you could modify a TV (with considerable effort) but then you’d have a TV with ‘shuttered’ horizontal lines and the image would be discontinuous (i.e. visible black lines between the image lines). So I think you probably mean to ask for less horizontal resolution, or wider lines - which would require repeating one scanline multiple times using something like a TV delay line: https://www.youtube.com/watch?v=-qerYLM-eEg
maybe I have to think properly about this. I’m using a Tektronix monitor, so I don’t have those TV constraints. I input XY and Z. I would like to have really less lines. Like 4 for examples to display. and image. I’m into the cadets to have more lines but what I’m after is raster manipulation, which also implies reducing/changing line numbers.
In that case yes, you could modify ramp generator frequencies to change the horizontal to vertical ramp ratio (which is the number of lines per field).
sounds like a job for the Castle series, dividing down the line count
If you’re trying to reduce the effective number of lines/resolution the scope will attempt to display, you’d need Chromagnon or a computer reading from a framebuffer in there somewhere.
Quoting Derek Holzer from a FB comment:
to the best of my knowledge you won’t be able to do reduced bandwidth scan processing in the analog domain, since all analog processes use synced ramps for this. What is required is some kind of digital frame buffer where pixel values can be addressed in an arbitrary way by H and V ramps (or other waveforms entirely: spirals are particularly interesting). My Vector Synthesis library does this, as does Ivan Marusic Klif’s REwerehere Max/MSP/Jitter patch, and this will be a feature of the upcoming Chromagnon module.
To give the appearance of thin horizontal bars being blanked out, you could do something like clock a Castle Counter with V sync and put that into the CV input of a Cadet X in 2Q mode (VCA). Then put your Luma into the VCA’s input and then out into your Z input. I don’t think that’s quite what you’re going for, though.
Thanks I was doing the same thing in Max/MSP too that’s why I’m looking forward to expand on that!! I’ll see whether I’ll get a Chromagnon then seems like it can do most of the stuff I need.