HP-25C Eumulator

[nsg]

Here is mine.

I discovered that if I file off corners just a little bit, it fits in the Altoids tin.

I thought it would not matter, but it seriously bothers me that registers are not preserved. I know it saves programs for hp25 and hp33 separately, but is there enough room to save full state of the "default" rom if you sacrifice the "other" program memory? I do not think I want to switch between them too often, but when I am using one of them I would prefer to have complete state saved for it and do not care about the other.