HP 2000 BASIC help / TREK73 - test-drb@ccmp.vtda.org

11 Nov 2003

On Nov 11,  1:27, John K. wrote:
...
  At 2003-11-10 04:17 PM, Pete Turnbull wrote: 
...
   I need some
help with some HP 2000 BASIC.  HP 2000 BASIC placed printing characters inside
double-quotes (") and used
...
  the apostrophe notation for non-printing characters. 
The apostrophe was
...
  followed by the decimal value of the character that
belonged at that point
...
  in the string.  Thus, any character in the extended
ASCII character set
...
  could be expressed using the apostrophe notation
('0 through '255). 
This makes sense.

...
  The '14 was used to instruct an HP terminal
(probably an HP2640, HP2645, or
...
  near the end of support for the HP2000 ACCESS, the
HP2621 and HP2624) to
...
  switch to the alternate (usually line drawing)
character set.  The '15 was
...
  used to switch back to the normal character set.

...
 From other information about the origin of TREK73 (see
Kermit Murray's 
page at http://ch309c.chem.lsu.edu/~kmurray/other/trek73/), and
knowing
where my listing came from, I'm pretty certain it was intended to be
run using a Teletype [AK]SR33.  On that machine, SO (decimal 14 is
Shift Out) would, as far as I remember, switch to the second colour if
you had a two-colour ribbon.  And SI (decimal 15) would shift back.
 OK, I can see a use for that, though it's slightly odd in that the
lines where it occurs aren't particularly special, and the text is
bracketed by a pair of '14, not by '14 and '15 as I'd expect.  My ASR33
only has a black ribbon, so I can't check if SO is cancelled at the end
of a line (I have a feeling it might be).  Oh, well, I better finish
typing and find a way of trying it out...

-- 
Pete						Peter Turnbull
						Network Manager
						University of York