HP-25 Prog Cose Puzzle



#4

I have noticed that the HP-25 accepts the key combination of 15 25 in program mode (g SUM+).

There is no blue key legend for this, so is it an undocumented instruction which does something? or is it a NOP?



Any help would be appreciated.

Thanks.


#5

As fas as I recall, it is a NOP by other OpCode...

#6

Oooops! sorry about the title!

Thanks for the reply, I can't see any effect of using 15 25 . Does anyone have knowledge of the ROM code?


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