This is for any one interested in putting in a z axis connection on your old scope that doesn't have one very simple hack too.
So the procedure in the Trio scope schematic example is brake the connection for the cathode pin 3 and connect a spare mains transformers primary between that and pin 22 rest explained below ...Should work for any oscilloscope just an example here as i have this scope .
Pretty much a very simple idea i don't know if it has been used in the past by any one else , the idea was and is just using a small mains transformer the primary 240 volt side is used between the cathode and its negative 1500 volt supply ...so only 2 connections .
The secondary which i think would of been 12 volts side is used for the modulation input just connected right from the lap top to ground and signal output connection just another 2 connections to that secondary .
So small signal about a 1 volt or so at best can modulation your scope if you don't have a Z axis connection .
It does rely on how high the video level is but every thing i tried seemed to work some files better than others but had not used any thing apart from this passive induction amplifier .
A speaker audio transformer i think would also work more than likely better,i was surprised it still worked without the one transistor amplifier i also recalled i used back 2 decades ago when i first tried this .
So results below with a 32 line video upside down and reversed ...least its not inverted
I will add a video amplifier transistor to this but not in the scope just to it ,but for using a little transformer and 4 connections a quick and dirty z axis modulation which i can't see why it can't be used on any old scope with out or a broken z axis connection as i had and just made it would with this idea .