Several days ago we informed that the HP12c is out of stock and it will be for several months due to the current scarcity of chips. What is available for the time being is the HP12C Platinum.
This is a different beast altogether. Issued as a development of the HP12c, it had several advantages over it and also several drawbacks:
1.5 times faster than the original due to a different processor and firmware in the Platinum version (a development of the 6502 processor of Atari and Apple II fame). The newer, ARM based versions of the HP12c are stil around 50 times faster than the HP12c Platinum, though.
much more memory - up to 400 program steps instead of the 100 of the plain HP12c
both RPN and algebraic numer entry
backspace - you just need to compare the old HP12c and the HP15c to know that this feature was sorely missing from the former!
A different LCD screen with different digit formats: taller and slimmer. (I prefer the former)
the bezels are silver instead of gold - just like the scientific Voyagers.
The colors of the keys and lettering are a much brighter orange-red and electric blue