Stable rasters on the VIC-20

[polluks]

What about the left border? See http://www.sleepingelephant.com/ipw-web/bulletin/bb/viewtopic.php?p=121320#p121320

[TomHarte]

If I'm going to look at the VIC again then there's definitely also a long-standing issue with background colour changes not being delayed for the proper number of pixels — so e.g. in the [semi-]recent port of Pitfall the background, which appears to be entirely a result of palette changes, appears shifted a few pixels to the left, making judgment of holes, etc, problematic.

Sadly I forgot to make a detailed note to myself on exactly how far delayed that's meant to be. So mild additional research also required.

[TomHarte]

Also, trivially confirmed that something there seems to be amiss. I don't have a good offhand guess as to what, sadly.

[TomHarte]

The problem turns out not to have been with the VIC itself at all (technically*), but to be in the way video data is streamed by the emulator. So: fixed. But not the other other VIC issues. I'll need to refresh my memory on the whole topic, I think.

* in that, technically, my VIC starts outputting the border level a little too close to the end of sync, and if it didn't then it wouldn't have triggered the issue, but the actual issue was an inadvertent completely incorrect response to that situation.