Stumbled upon your old calculator and was very surprised that it works, the batteries are exhausted.
This calculator MBL I bought about 1989, when I started to program in assembler BK0010. He had a unique feature - it could be considered in the different number systems, including octal, in which the processor 1801VM1 worked. With my operating system ANDOS created this calculator (https://ammo1.livejournal.com/162719.html).
In memory even keep the number. Interestingly, when it was made there? Almost certainly not in the last 20 years.
The calculator is powered by two silver-zinc batteries.
The date on which, unfortunately, no. Only type 389A.
I do not remember whether I have changed ever batteries in the calculator. Perhaps that is not. In the far-distant box, where the calculator would be found, I looked no less than thirteen years.
In any case, surprisingly, that the batteries are not sat at such a great time. It is even possible for all 30 years of the life of this calculator.
© 2019 Alex Nadozhin
The main theme of my blog - Equipment for human life. I write reviews, share experiences, talk about all sorts of interesting things. My second project - lamptest.ru. I test LED lamps and help figure out which ones are good and which are not.