![composite for sync checker composite for sync checker](https://blackwells.co.uk/jacket/l/9781118485286.jpg)
![composite for sync checker composite for sync checker](https://cdn.statically.io/img/sportsclinictampico.com/wp-content/uploads/2021/10/how-sync-chrome-BB06A.png)
Modern stuff will not have trouble with that but will certainly give some headaches to achieving a proper timing doing so without all the necessary surrounding paraphernalia Paul the local oscillators do some magic stuff to proper lock the V and H synch train pulses and without the magic synch separator tricks these locking frequently fail. as they were never intended or designed at that time to work without a transmitter/receiver schema On the RECEIVER side. obviously all drawbacks appears as annoying problems. Equalizing pulses, shifted sub carriers each (PAL/NTSC), and even intrinsic details on RECEIVERS in which the MAIN PHASE (50 or 60Hz ) plays a decisive role. Channels were in sight and cramming so much stuff inside them required some creative solutions.
![composite for sync checker composite for sync checker](https://c1.neweggimages.com/ProductImageCompressAll1280/24-116-840-S04.jpg)
so this is the main reason for these "magic numbers". they where were designed for transmission. PAL and NTSC were never intended when designed to work outside a full carrier transmission profile. Have they been adjusted slightly to compensate for some of the NTSC specification simplifications mentioned at the start? Or is it more likely that voltage drop is the real culprit, and it is coincidence that these adjusted timings seem to work? Thanks. If I plug these values into my program I get a good stable picture, which is great, but I'd like to understand why these specific timings (which don't seem right) seem to work. Looking at the source for Arduinocade ( ), lines are actually 63.7303003530484usec, and the colorburst begins at 6.2usec (TICKS_HBLANK). I've got some PCBs on the way in 2-3 weeks which should resolve this. I've tried using a power bank as a substitute power supply but its output was noisy and well above 5V at the low current draw this circuit has.
![composite for sync checker composite for sync checker](http://sgcdn.startech.com/005329/media/products/gallery_large/VGA2CPNT.C.jpg)
I will note here that I'm having trouble with voltage drop on the breadboard I'm using for prototyping it's about 0.5V below the target 5V at the IC. I have verified that the program is producing the expected signal timing using a pocket DSO. When I generate a signal using the closest available approximations of these values, my test displays (a car reversing camera display with composite input, and a USB capture card will have access to a real CRT from next week) don't seem to get a good vertical hold lock and the signal is interpreted as greyscale. I've been configuring my AVR to produce a NTSC signal based on this diagram from Maxim (from ): My understanding here is that the line should be 63.5usec long, and the colorburst should begin 5.3usec after the falling edge of the HSYNC pulse. Of course, being similar to a retro console or retrocomputer, Arduinocade doesn't implement the NTSC specification to the letter it only uses one field (so 240p60hz), doesn't include equalization pulses, doesn't adjust timing for VSYNC lines (they're single-pulse normal length lines rather than double-pulse 64usec lines) and uses artifact colors rather than generating real sine waves at 3.7MHz. I've done a lot of research into how NTSC works and feel I've got a good understanding. Hello! Recently I've been tinkering with Arduinocade and having a go at writing my own implementation.