> > $C8 is described in my book as "number of watched WHEN variables"
>
> Ah! Jan Jones When variables - has anyone ever described this
wonderful
> unimplimented facility?
>
> Tony Tebby
It seems a wonderful facility. Something like:

WHEN entry=-1
  PRINT"Don't enter negative numbers, mate!"
  RETRY
END WHEN

would potentially be useful, but I don't know how it's meant to work
in SBASIC. I vaguely remember back in the 1980s that very early ROMs
(the first external eproms?) had a keyword called BECOMES, implying a
syntax of something like WHEN var BECOMES <value> I suppose. It's
obviously not in official Sinclair ROMs or anything else modern.

SMSQ/E at least doesn't seem to allow an entry of the example I typed
above - so the syntax is definitely not WHEN var=value or WHEN var in
SBASIC, I've never been able to figure out how it works if it works at
all in SBASIC.

Minerva claims to be able to use it (Laurence...are you there?),
here's some info from the manual:

The Minerva manual lists an example along the lines of the above:

WHEN a=6
PRINT 'a is now six'
END WHEN

Single line WHEN should work, like the equivalent FOR, REPeat, IF etc.

When Variable processing can be turned off with  WHEN a  (that is,
specifying a variable name but no value test), and WHEN anything (i.e.
any name) will turn off all current WHEN processing.

It does not specify how to resume processing from such a WHEN clause,
but presumably once END WHEN is reached, normal execution CONTINUEs?

End of essay :-)

--
Dilwyn Jones

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