Is the following a known HP33S bug?
Subtract ONE DEGREE from ONE MINUTE and you should get NEGATIVE 0 DEGREES 59 SECONDS. However, the HP33S returns NEGATIVE 0 DEGREES 58 MINUTES 20 SECONDS.
If you subtract ONE DEGREE from 4 MINUTES, you should get NEGATIVE 56 MINUTES, but instead, the HP33S returns NEGATIVE 55 MINUTES 20 SECONDS.
Am I doing something wrong?
>> you should get NEGATIVE 0 DEGREES 59 SECONDS
Sorry about the typo... I should have typed NEGATIVE 0 DEGREES 59 MINUTES 0 SECONDS...
The ->HMS function on the 33S has a bug; it does not always work correctly with negative numbers. It apparently can be trusted with positive numbers. This has been documented by HP in the "User's Manual Update" at
http://h10032.www1.hp.com/ctg/Manual/c00251639.pdf
I programmed a simple "alternative" ->HMS function on my 33S, which is assigned to XEQ 5 (instead of right-shift 5). The "alternative" function checks to see if the input is negative. If it is, then it changes the sign, runs ->HMS, and restores a negative sign to the result. The program uses flag 4.
LBL U
CF 4
x<0 ?
SF 4
FS? 4
+/-
->HMS
FS? 4
+/-
CF 4
RTN
You should also be aware of the polar conversion bug, which is also documented in the "User's Manual Update"