Forbidden64 wrote:Okay, good point. So the former might be worth a try, but if it is internal to the chip(and it very likely is), it is still buggered, or at least partially so no matter what.
Nope, not 'no matter what'. As I said earlier, the 1351 method circumvents the problems. Instead of charging a capacitor and let the VIC-I compare it's level with some reference voltage which happens to be unstable, create a circuit which counts the number of charging pulses and simulates a fully discharged cap (well below the ref voltage) before the desired value then a charged cap (well above the ref voltage) once the number of desired pulses is reached.
Now here is where I wish I had more knowledge on the subject, and perhaps you can help me finish this thought. In an LVDS circuit for example, the reference to ground is used to eliminate noise by tightly coupling them via running them very close together. Since it is reference based voltage, it can completely eliminate anything that inducted on the trip, because it is reference based. Excluding the idea of tight coupling, but in the same vein, could it be possible to use an external reference between Vcc and GND [to clarify, Vcc and GND pins on the chip itself...literally running a cap over the top of the chip) using some component to eliminate the external affects of this internal ripple? Or would that make it worse... There is a nebulous intuition in my mind that something like this could work.
A very complicated way which will have virtually no effect on the impact caused by the internal power ripple.
The 1351 method is a thousand times better.
... technical vulgarisation.
Imagine you are the (slow) VIC-20 and you're filling a cup with water one teaspoon at a time and counting the number of teaspoons required to fill the cup in order to tell the size of a ball of metal you dropped in the cup. The exact number of teaspoons you'll need won't be exactly the same every time you fill the cup - the teaspoon is imperfect and the cup shakes.
Now, somebody who is a thousand times faster than you is playing tricks on you. You pour teaspoons of water into the cup but the water level doesn't rise because there is a hole at the bottom of the cup. Then, after exactly 173 teaspoons, the cup is magically instantly full of water. You empty the cup and redo the same thing, once again only to see no water accumulate in the cup and once again, after exactly 173 teaspoons, the cup goes instantly from empty to full. It doesn't matter anymore that the teaspoon is imperfect and the cup shakes.
That is the equivalent to what the 1351 does.
No one can do everything. Everyone can do something.