KGB Superspy (ZX Spectrum)
KGB Superspy is a game where you pilot a helicopter to pick up East German scientists and help them defect to the West. It's very much of its time and was written toward the end of the Cold War.
At 0x529E is a small message.
REAL PROGRAMMERS ASK FOR CHRIS ON 098683 758 or 0728 724460. Dass ist eine Englische nummer.. Tschuess
The German simple translates as "That is an English (phone) number. Bye." Chris refers to programmer Christian Pennycate.