I have taken my HP-25 out of the drawer and after some new batteries it works fine. This is a very early unit, serial number 1509A13072. (Second week of production?) After I bought this unit I got a recall notice from HP about a defect in the calculator. I did not take them up on the repair.
I don't remember details but if you were using a stored program and saved a value (1 x 10 -25 or something) in some memory location then switched to program mode, the calculator would crash. (It helped if you were standing on one foot.) I was able to reproduce the error back then but I don’t remember the exact sequence now.
Does anyone have any information on this? I will be here pressing keys until I reproduce it.
Michael Holley