Scientific calculators that have formula/equation memory

[pier4r]

After this thread and the analysis of Dieter (in the same linked thread), I would lean more on the fx5800p rather than the 35s. Moreover the 5800p seems to have persistent memory (with the 35s one has to be careful to swap the batteries, as reported in this thread). This because the 35s and the fx5800p at the moment have prices quite close.

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Recap. For more info, read the entire thread and links in various posts.
Scientific calculators with ability to store formulae (in programs or direct formulae) still in production:
- Hp35s. ~ 30K of ram
- Casio fx5800P ~ 25K of ram.
- swissmicro DM42 (programs as formulae).
- swissmicro DM15 with registers and program memory (program as formulae) ~1500 bytes program memory.
- Many sharp models have 9 memories and 4 formula memories.

- hp35s : 6.22 in x 3.23 in or 15.80 cm x 8.2 cm
- Casio fx5800P: 6.4 in x 3.2 in . 16.25 cm x 8.12 cm
- DM42: 144mm*77mm
- DM15: 88mm*59mm
- Sharp models: round about 160mm*80mm

Any other suggestion is welcomed.