It rained the day I visited the place, and since it was an old building, it actually rained a bit inside. The guy took it with humour, but it was actually a pity. It is a great place and on some days the visitors can even run old programs on those ancient machines or play games.
From their site: Opened on 22nd of September 2007, Club PEEK&POKE is one of the few permanent displays of vintage computing technology in Europe. Located in the centre of the city of Rijeka and spread across 300m2 of space, it contains more than 1000 exhibits of the world and local computer history, ranging from very early calculators and game consoles to rare and obsolete computers from the nineties.