ZCN v1.2 bug fixes
------------------

NB: If you have a version of ZCN other than v1.2 you should ignore
these fixes; they only apply to ZCN v1.2 (distributed as `zcn12.zip').


The `man.com' distributed with ZCN v1.2 has a fatal bug which causes
it to crash in just about any circumstance. It's only due to
practically unprecedented idiocy on my part that I failed to notice
this before releasing it. My heartfelt apologies go to anyone who got
bitten by this bug. :-(

The `man.com' here is fixed, and should be used instead of that
distributed with ZCN v1.2.


There are two other bugs in ZCN v1.2, though these are much less
serious in practice:

- If you ask rrxfer for a list of the ROM files and there are none, it
  crashes. Obviously if you have any files there you're ok :-), but
  for those who want a slightly better fix, a corrected version of
  `rrxfer.com' is included here.

- Only 1992 and 1996 are recognised as leap years; 2000, 2004, etc.
  aren't. Interestingly, this isn't the obvious Y2K-ish problem, it's
  rather due to ZCN programming the real-time clock chip's leap year
  counter incorrectly in most cases. ZCN v1.3 will include a full fix
  for this - however, a quick fix to make v1.2 recognise 2000, 2004,
  and 2008 as leap years is to do this (at the ZCN prompt):

			     poke c85d 0

  You can then do `sys a:' to save this patched ZCN to memory card.
  Then you should use `timeset' to set the time and date. Note that
  it's important that you set the time *and* date - fail to do this,
  and the old (incorrect) leap year counter setting will remain
  intact!

    For those interested in how this fix works:

    The bug leads to only a period of ten years working correctly (I
    treated a BCD number as decimal, whoops!) - but by a sheer fluke,
    the way I wrote the code means it's easy to pick *which* ten years
    you get. :-) It does mean that 1992 and 1996 won't be treated as
    leap years, but as I say, ZCN v1.3 will include a complete fix for
    the problem. (I've already written the fix, it's just that the
    above approach is the only way to fix v1.2 easily.)


Sorry for any problems the above bugs have caused, ZCN v1.2 looks to
have been the most buggy thing I've ever released, and that's quite
some achievement. :-}

-Rus.
