fraction program hp 28s?

[Peet]

It seems fractures were a thing on the 28s back then, I found this in my old notes from the late 1980's:

Bruchrechnen:

GGT (größter gemeinsamer Teiler)
<< DO DUP 3 ROLLD MOD DUP UNTIL 0 == END DROP >>

KGV (kleinstes gemeinsames Vielfaches)
<< DUP2 * ROT ROT GGT / >>

STATUS (setzt Standartflageinstellung, 4 FIX usw.) e.g. Flags {31,35-42,48,49,52,55,59,63}
<< #4920609187307716608d STOF >>

D->BR (Dezimalzahl als Bruch anzeigen)
<< STD DUP DUP IP ->STR " " + SWAP FP 1 DUP2
DO DUP 3 ROLLD MOD
UNTIL DUP ,00001 < END
DROP 0 FIX DUP 3 ROLLD / RND 3 ROLLD / RND
STD ->STR "/" + SWAP ->STR + + CLLCD 2 DISP STATUS
>>

Note: it was important to use the correct decimal separator (./,) according to flag 48 settings.