This building was to be demolished. You wouldn't believe what was inside. | IME 84 repair

[@douro20]

Apparently this was the first calculator product of the Italian company IME (Industria Macchine Elettroniche) and one of the first produced fully transistorized desktop calculators. I believe division is done by entering the dividend, then pushing the divide key, then entering the divisor and pushing the "divide equals" key to the left of the divide button.

[@senilyDeluxe]

That's one of the buttons I still need to unstick. Also, two or three of the buttons I got unstuck are back to sticking again. I'll try it out. The machine seems to have bad card edge connectors, I went through every transistor and diode on every card and when I put the machine back together, it didn't work at all. Removed them again, tested again, found nothing, put them back, partially working. Jiggled the cards until at least addition was working 100% again.

[@douro20]

I like the old Monroe automatic calculator. The one I have is a mid-60s one, one of the first models of the IQ series which has a 2.9 digit decimal counter register (two before the decimal and nine after with automatic tens carry).

[@senilyDeluxe]

I already gave it to another collector. He tried it out and it appeared to be mostly working. After a few minutes, the FI blew and the entire retrocomputing exhibition was dark. Later it turned out to be a Commodore 128's line filter (which even started bulging, it's a metal can one nonetheless!) EDIT: For clarity, I'm talking about the Monroe. I still have the IME-84.

[@daddlertl3]

DIe Verkabelung in dem Gerät sieht fast so aus wie in einem elektromechanischen Flipper, nur hat man hier die Relais durch Transistoren ersetzt (war wohl doch ein bisschen platz- und energiesparender).

[@eDoc2020]

I would check the high voltage power supply. If it's weak that could explain why some digits are slow to strike.

[@senilyDeluxe]

Pretty much every transistor in this machine that I measured was leaky and the PSU ones are surely no exception. Also the 100V replacement capacitors only measured slightly -better- less bad than the ones that were in there. But eventually all nixies strike and I'm lazy. Btw. update: I fixed the stuck keys and Testofoned every single transistor and diode and couldn't find any that were bad. I encountered some weird behaviour that could be traced to bad contacts, but now the machine appears to work fine. Still no idea how to multiply/divide.

[@douro20]

@@senilyDeluxe I have hundreds of old TO-5 package germanium transistors- most of them PNP- which came out of an old Dymec digital voltmeter. I tested every single one with a Heathkit IT-18 transistor checker which I acquired at the same flea market.