[BBC-Micro] Grrr.....annoying master cmos ram

[Jonathan Graham Harston]

>Message-ID: <38370.82.71.113.222.1163085016.squirrel at webmail.starfleet-net.co.
 
"Richard Gellman" <splodge at starfleet.homeunix.net> wrote:
> Curiously, the Ahkter floppy disc user guide says of "Bad Sum":
> "We have never seen the error occur, and don't believe it exists."
> It is in fact a DFS error, but as the user guide implies, its never seen
 
No, it's an ADFS (as Sprow pointed out) and an ANFS error. It will
occur if you corrupt the workspace above &C000. The only way to
get rid of it is Ctrl-Break. Sometimes even that won't do and
Power-On or *FX151,78,127 then Ctrl-Break is needed.
 
> a) difficult to get hold of with visiting specialising sites (such as
> those run by various members of this list) as this chip effectively *is*
> the millenium bug* (its the chip that doesn't go past 1999, which was
 
That's not the IC, it's the controlling software. The IC only
keeps a two digit year counter. It's up the the controlling
software to use that two-digit year appropriately. For example,
some versions of RISC OS have a 'current century' byte in CMOS.
Sensibly, the MOS should have implmented code that returned
1980-2079. There's plenty of space to fit it in, as described on
the Abu Dhabi Shipping Company's website.
 
-- 
J.G.Harston - jgh at arcade.demon.co.uk - mdfs.net/User/JGH
BBC BASIC for 30+ platforms - http://mdfs.net/Software/BBCBasic