Possibility of assembly programming on HP 42S

[yardmax]

I am very curious about the possibility of programming direct machine code onto an hp42s through either the built in monitor or some rpn bug. I can't seem to find much info on the topic. Also, what is the possibility of ruining the calculator or making it unusable? I know that a memory reset would be pretty easy to cause, but I absolutely do not want to brick my 42.

Thanks in advance,

-Jack

[G-SAN]

From what I have learned so far:

you *can* program machine language in the memory of the 42S using the internal debugger, but only by entering the HEX code directly into a memory location (eg. 52000).

However, the only way to use this code is by using the debugger to go to the starting point in memory of your code and pressing "."

Another option is to open the 42S, add a RAM of FRAM chip to the printed circuit board, write the code to "decode" an XFCN instruction (decoding the string in the ALPHA register and then executing the ML code for that function).

But this second option is only possible if you are:
willing to open up your 42S
capable of adding an extra memory chip (soldering)
understand the electronics involved so you do not zap (electrostatically) your dear 42S.
have tools to translate assembler into hexstrings you can type
have loads and loads of patience and the focus of a Jedi to type hex codes without mistakes

It is clear to me that only very few people could do this, and it is certainly not as repeatable als coding ML on HP48/49.

The chance of ruining your 42S when extending memory is certainly there.

But is all this practical ? Nope !
Would it be a challenge, yes !

Hope this helps