Here are some thoughts, though perhaps no complete "solution" -- sorry!
allisonlastname wrote:
Can you only manipulate CB2 directly when the shift register is disabled?
That sounds right (although I haven't checked).
Quote:
[...] owing to the fact that the VIA's SR skips the first input bit unless you put a flip-flip in the way.
Adgain, I haven't checked. But I would've though the extra flipflop you mention is required only when the VIA inputs a clock signal that's generated externally (rather than outputting a clock that's generated internally). Suggest you search the forum (or Garth's site) for doc on VIA bugs.
Finally, your RCLK issue will disappear if you switch out the '595 and instead use a '299 or '323. These chips don't have a separate storage register, so the RCLK signal doesn't exist. Just a suggestion. Have fun!
-- Jeff
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In 1988 my 65C02 got six new registers and 44 new full-speed instructions!
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