About use of the MVCDK instruction Rob Scott writes: <begin extract> That is fine for fields where you are replacing the entire contents - but how about an individual bit in a status byte for example where normally you would use OI/NI or OIL/NIL ? </end extract>
and I am not persuaded. Here 'field' means addressable unit of storage, i.e., byte. In resetting a bit one can ordinarily---in my experience always---calculate the new containing-byte value painlessly and then replace it as a unit. Moreover, one usually wishes to avoid moot operations of this kind (or at least to distinguish moot and non-moot ones). That said, Rob's posts in this thread have been particularly valuable; and I would not want this nit picking to suggest that I think otherwise. John Gilmore, Ashland, MA 01721 - USA
