No experience with radar but wouldn't sawtooth waves amplitude modulated by sine waves produce a rotating radial scan if the sine waves were 90 degrees out of phase?
Generating those sawtooths at the radar pulse frequency and sine/cosines at half a hertz or so and keeping it all in sync with the radar pulses and rotation would have taken a lot of tubes back in the day. Smaller and easier to just rotate the deflector coils mechanically.
During my time this was all done with big boards of digital circuits driving ADC's.
BTW, CGA is still used in many old CNC milling machines. If a monitor breaks down you have to spend huge amounts of money to find a replacement. So a device that converts CGA to VGA which can be displayed on any modern LCD monitor would be helpful.
Unfortunatelly, the propeller has a fast video-out hardware but no video-input. And 4.77MHz is to high to sample it in software via bit-banging. So at least an external shift register (or rather 4 for RGBI) would be necessary.
eBay has tons of cheap CGA/RGB to VGA converters. I bought one for $15. They aren't the best quality. But if you get a good signal in they are certainly usable.
I can dig up the model number if you're interested.
Many people use them on Atari's and Amiga's (oh, and arcade machines) so they can use cheap VGA monitors.
Comments
Generating those sawtooths at the radar pulse frequency and sine/cosines at half a hertz or so and keeping it all in sync with the radar pulses and rotation would have taken a lot of tubes back in the day. Smaller and easier to just rotate the deflector coils mechanically.
During my time this was all done with big boards of digital circuits driving ADC's.
Unfortunatelly, the propeller has a fast video-out hardware but no video-input. And 4.77MHz is to high to sample it in software via bit-banging. So at least an external shift register (or rather 4 for RGBI) would be necessary.
eBay has tons of cheap CGA/RGB to VGA converters. I bought one for $15. They aren't the best quality. But if you get a good signal in they are certainly usable.
I can dig up the model number if you're interested.
Many people use them on Atari's and Amiga's (oh, and arcade machines) so they can use cheap VGA monitors.