DMS: creates a "degree-minutes-seconds mode" similar to the built-in
polar mode.  By Joe Horn.


INSTALLATION: DMS is a directory containing 4 programs:

    DKEY - starts DMS mode on level 1, with DMS softkeys.
    DEGS - one-shot display routine used by DKEY.

    DK2  - starts DMS mode in status area, with DMS softkeys.
    DEG2 - one-shot display routine used by DK2.

Just load DMS into memory and enter the directory.

If you wish, you may copy these programs into the HOME directory, and
then they will be available at all times.  If you only find yourself
using one pair of programs, feel free to purge the other pair.


GUIDED TOUR:

(1) DKEY

  Press DKEY.  See DEG, MIN, SEC, and EXIT softkeys.  Press 1 DEG and
  see 1ø 0' displayed on level 1 of the stack.  Press 3 / and see 0ø
  20' (one third of a degree).  Press 7 MIN and see 7 minutes added to
  it: 0ø 27'.  Press 15 SEC and see 15 seconds added to it: 0ø 27'
  15".  Press +/- and see its 360-degree complement: 359ø 32' 45".
  Press 1.75 - and see 1.75 degrees subtracted from it: 357ø 47' 45".
  Press 47 +/- MIN and see 47 minutes subtracted from it: 357ø 0' 45".
  Perform any math you like; the answer is automatically displayed in
  DMS format on level 1.  Press ON to see the angle in decimal format,
  and press EVAL (or perform any math) to return to DMS format.
  Press EXIT to exit DMS mode.

(2) DEGS

  Press 8 1/X DEGS.  See 0ø 7' 30" (one eigth of a degree) displayed
  on level 1.  Perform any math you wish on this number (or press ON),
  and it returns to decimal format.  That's all that DEGS does: it's a
  one-shot DMS display of whatever is on level 1.  It does not launch
  any sort of "mode" and so you don't have to "exit" from it.  Having
  DEGS assigned to a key is handy when you just want to see the DMS
  form of a single number without launching DMS mode.

(3) DK2

  Now try DK2.  Use it exactly as you used DKEY, described above.  The
  only difference is that the DMS display is not on level 1, but in
  the status area.  Some people like it better this way, because you
  can see the decimal format on level 1, and the DMS format in the
  status area, simultaneously.  Press EXIT to exit DMS mode.

(4) DEG2

  Try using DEG2 exactly like DEGS, described above.  Again, the only
  difference is where the DMS formatted number is displayed.


FINE POINTS:

The DEG softkey merely does an ENTER, so you may press the ENTER key
instead of DEG if you wish.  The MIN and SEC softkeys, on the other
hand, always perform an addition, so if you want to enter an angle
less than 1 degree, be sure to first press 0 DEG (or 0 ENTER).

DKEY and DK2 turn on USER mode and require it to be on to work
properly, even though they do not create nor require any key
assignments.  They both turn off USER mode when you press the DMS-mode
EXIT softkey.  If this is not desired, remove the -62 CF from DKEY and
DK2, near the middle of each program.  They also create a variable in
the current directory called 'betaENTER' (looks like BENT in the VAR
menu) which is also required for them to work properly.  It is
automatically purged when you press the DMS-mode EXIT softkey.
Finally, they also set system flag -63, the vectored-ENTER flag, and
clear it when exiting DMS mode.

DMS mode does nothing when anything other than a number is on level 1
of the stack, and it never has any effect on any other levels of the
stack.

Accuracy: Seconds are displayed with a maximum of four decimal places,
with any necessary rounding propagating upwards into the seconds, then
the minutes, and then the degrees.  Thus the displayed angle is
guaranteed to be the closest DMS representation possible (to four
decimal places in the seconds).

Angles are always modulo 360.  That's why multiplying 12 degrees by
100 does not produce 1200 (as might be expected), but 120, because
that's the right answer when reduced mod 360.  This is also the reason
why negative angles "wrap around" mod 360.

These programs are 100% User RPL, and can be easily edited.  Leave the
SYSEVAL arguments alone, however.

A similar program called FIF, which puts the HP48 into a similar
"Foot-Inch-Fraction mode", is also on this Goodies Disk.