Artifact in text mode

[gardners]

In C64 mode the following code:

POKE53280,0:POKE53281,1:POKE646,0:POKE199,1:FOR T=1 TO 800:?" ";:NEXT T

shows a thin white line on the right side just before the border starts but after the screen content ends. It looks as if the content of the screen is displayed half a dot-cycle too early...

It seems that this also affect the C65-mode. If you run the following basic code in C65-mode just after booting up the machine:

FORT=1TO1000:?"R ";:NEXTT (The R in the print string is CTRL-9 (Revers mode on))

you can see (beside other wired horizontal lines that are appearing on screen) that the white screen content does not align with the yellow border on the right side. You can see a small blue line of the background color. In addition I think it overlaps half a dot-cycle on the left side.