Interesting Vector Graphics Project from all of those years ago.

[top204]

I purchased a few old electronics magazines on sunday at a car boot sale, and came across one I remembered having when I was a young-un, and always wanted to build the circuit in it, but could not afford the pieces, and in 1984, was still in mourning over the passing of my lovely dad, so it never got built. But it triggered a strong impulse in me, when I saw it. :-)

When time is spare, I am going to try to build it, but with some modern components, and a microcontroller, and some external components for the 'Sample and Hold', because it has some very interesting aspects to it that I never thought of. And I want to use the good old LM13600 or LM13700 Transconductance amplifiers again. At the time, they were like magic, and could perform tasks that previously required quite a few components, or expensive 'dedicated' components!

I did experiment with vector graphics on an oscilloscope about 12 years ago, but dropped it because I was too busy making someone else money and reputation. :-(

See what you think about the project for vector graphics on the lovely ZX81 computer, in the magazine below:

Electronics Today International - 01-1984.pdf

The 'www.worldradiohistory.com' site is good, but the scan quality of a lot of the downloads is not always very good.

That was when electronic magazines were actually worth buying and reading, and there were quite a few of them available each month for a 'few bob' each ('few bob' is a saying in the UK for 'not a lot of money', because a 'Bob', was a 'Shilling' coin). 'ETI' was an excellent magazine, and so was the short lived 'Hobby Electronics', among others.

[Wimax]

I like the Chorus/Flanger project very much ! 

[top204]

The Bucket-Brigade devices are excelllent, and I have used them in the past for a simple reverb, chorus, and flanger.

They are a bit noisy when trying to get too much delay from a chip, using a slower oscillator feeding them (bandwidth), or daisy chaining too many ICs for more delay, but that can be improved a lot by using a compander circuit with an NE570 or NE572 chip for the input and output. So it compresses the input signal, and expands the output signal. i.e. 'Compander'. I remember that if you made the electrolytic capacitors a bit too large with the NE57x chips, it got a noise that sounded like a faint whisper 'whooosh' sound when the compression and expansion first took action, but when they were set correctly, they were excellent at noise reduction.

I once made a replica WEM echo using bucket-brigade chips, so it had multi taps that imitated the three heads of the tape echo, and each could be turned on or off, and each had a depth knob. I still remember that it sounded excellent with a guitar, because the tape echos were noisy themselves, so it sounded just like a tape unit. Crickey.... That was 35 years ago!!!!!

Ohhhhh, The good old days. :-)

[ken_k]

Vectrex

https://www.youtube.com/watch?v=yUB6OYeCKek

https://www.youtube.com/watch?v=8Dv15YRAmzM&t=12s

[top204]

Back in around 2004, I had the chance to buy a Vectrex machine at a car boot sale for £20, but at the time, I thought it was not worth that much (which it is not IMO), and that was before the bubble expanded with the old 8-bit computers, with idiots who have more money than sense paying silly money for them, which prompted the sellers to be greedy, in an ever increasing profiteering for the stupid, cycle. I used to buy the old computers for £1, £2, and maximum £5, for the sake of nostalgia, and the love of them. :-)

But now they are used as "assets", because there are so many idiots out there! I just wish I had learned how to manipulate the idiots with more money than sense, but my decency stopped me, and instead it was me who was manipulated.

The Vectrex was a clever item, but not worth the money they wanted for it at the time in the 1980s, and it was not actually very good. But, ohhhh how I wish I knew then in 2004, what I know now, and I would have snapped it up.

It will eventually be like the idiots in the Tulip Mania, in Holland, back in the 1600s, where rich idiots payed huge amounts of money for tulips, then when the bubble burst, they were left with useless crap that they had spent a fortune on, and were not worth anything. :-) Do I feel sorry for rich idiots?? I'll leave it up to you to guess my answer. ;-)