Very clear and complete explanation. Thanks John! With many cheap microcontrollers like Raspberry Pi Pico is possible to drive a vga monitor with few components and a lot of coding, and to achieve that all this information is crucial.
@BenEater has a great project on making a graphics card from scratch that outputs a VGA signal (which can be connected to a VGA monitor). Building a VGA output device makes it easier to understand the protocol as a whole.
22:48 Not true... Old monitors can tolerate a (relatively) wide range of vertical sync frequencies. However, if the horizontal deflection coil is connected to the flyback (to save on cost and to some extent stabilize the image), an incorrect horizontal sync frequency can mess up the flyback. The flyback circuit is usually tuned to a set frequency and would not tolerate a large deviation. What will usually happen is that the monitor will work but display garbage on screen (since it cannot get proper sync) and if you don't turn of the screen/disconnect the signal quickly it will burn itself out.
Oops 😬... Memory don't be failing me like this!!! Sorry. I should have fact checked that digression. Even so, anyone using a glass CRT needs to be careful if they leave the confines of the spec standards.
interesting. I Remember when vga first came out. it was interesting how the different monitor, cables, and cards did not play well with each other. Then stuff seem to settle out. Then vesa with edid came along and another round of pieces not play well with each other.
All the mistakes in texts and diagrams show that the authors don’t know the subject intimately.❤ If the video signalling timing is too discrepant some CRT monitors blow up either or both their horizontal and vertical deflection circuits.😢 VGA was introduced around 1987 with IBM’s PS/2 system along with the ill-fated microchannel architecture. 🎉
Very clear and complete explanation. Thanks John!
With many cheap microcontrollers like Raspberry Pi Pico is possible to drive a vga monitor with few components and a lot of coding, and to achieve that all this information is crucial.
Very nice. I knew some of this but it's nice to tie it all together. Thanks.
@@gregorymccoy6797 you're welcome!
@BenEater has a great project on making a graphics card from scratch that outputs a VGA signal (which can be connected to a VGA monitor).
Building a VGA output device makes it easier to understand the protocol as a whole.
Great video John!
@@joeysartain6056 thanks!
22:48 Not true... Old monitors can tolerate a (relatively) wide range of vertical sync frequencies. However, if the horizontal deflection coil is connected to the flyback (to save on cost and to some extent stabilize the image), an incorrect horizontal sync frequency can mess up the flyback. The flyback circuit is usually tuned to a set frequency and would not tolerate a large deviation. What will usually happen is that the monitor will work but display garbage on screen (since it cannot get proper sync) and if you don't turn of the screen/disconnect the signal quickly it will burn itself out.
Oops 😬... Memory don't be failing me like this!!! Sorry. I should have fact checked that digression.
Even so, anyone using a glass CRT needs to be careful if they leave the confines of the spec standards.
i ordered an ice40hx yesterday :)
@@ChrisJackson-js8rd fun times ahead!
interesting. I Remember when vga first came out. it was interesting how the different monitor, cables, and cards did not play well with each other. Then stuff seem to settle out. Then vesa with edid came along and another round of pieces not play well with each other.
@@allenlorenz they call that progress! 😂
All the mistakes in texts and diagrams show that the authors don’t know the subject intimately.❤ If the video signalling timing is too discrepant some CRT monitors blow up either or both their horizontal and vertical deflection circuits.😢 VGA was introduced around 1987 with IBM’s PS/2 system along with the ill-fated microchannel architecture. 🎉