6560 PIN 4 (R/W) - looks a bit strange, is this a floating input? Do you get the same pic on your good Vic (I don't have a scope so can't tell).
http://archive.6502.org/datasheets/mos_ ... 61_vic.pdf
(mod: repaired botched OCR from PDF file and put in quotes. "RA/V" in fact is R/W and it's the PΦ2 signal mentioned here.)Read/Write— Pin 4
This signal is an input only on the 6560 and controls the flow of data between VIC and
the microprocessor. When the R/W signal is low and the VIC chip select conditions have been
satisfied, the microprocessor can write data into the selected VIC Control Register. If the R/W
signal is high and the chip select conditions have been met, the microprocessor can read
data from the selected VIC Control Register.
It is important to note that all VIC/microprocessor data transfers can only occur when
PΦ2=1. During PΦ2=0 the VIC will be fetching data from memory for display and the R/W
signal must be held high to insure that VIC will not write into any memory location.