Posts: 1,107
Threads: 159
Joined: Jan 1970
Hi. It does look like a previous owner etched the S/N onto the back of the calculator. Brings up an interesting question...why wasn't there a S/N there already? Doesn't seem like it was there to me, unless the person who etched the S/N onto the 41c did it right over the original.
The series of key presses I gave you allows a very early 41c with a bug called "bug 3" to set the system flag for the low battery indicator. This is not normally possible on a 41c, but these early ones could do it in the way I described.
Good looking 41c, regardless! :-)
Posts: 234
Threads: 33
Joined: Jan 1970
Guillermo,
Nice photos. Serial number appearance is quite different from my units (2452S41134, 2133B94184).
By the way - it looks like the plastic frame that goes between the two halves of the case is mounted upside down.
Saudacoes do Brasil.
Renato