I used to be able to locate the computer section of WH Smiths or John Menzies in the 1980s and go and play on the ZX Spectrums and Commodore 64s (and other oddi

I used to be able to locate the computer section of WH Smiths or John Menzies in the 1980s and go and play on the ZX Spectrums and Commodore 64s (and other oddities - the one in Arbroath had a couple of Memotech MTX512s!) by hearing the 15kHz scan line whistle from the CRT tellies they used for displays.