actually, there was no such thing as a sinclair spectrum until late 1981 / 1982 the only 'home computers' in mid 70's were prohibitivley expensive and few and far between the 2 best machine of the 70's was the atari 400 HANDS DOWN. bearing in mind that the ZX80 was released in 1980 and the ZX81 was released in 1981 and the spectrum came after them, i find it hard to believe you were making modem connections in the 70's, but were getting old now and dementia is most prolly setting in
incidently, the spectrum was designed and made less than 50 miles from me.
what year is this again? who am i? damn it's tuff getting old.
Ohd Chinese Ploverb say : Wise Eskimo, not eat yerrow snow.