On Saturday, 11 April 2020 13:01:42 UTC+1, Bob Eager wrote:
ISTR there was an even earlier one that used the phone keypad.



Yes, you had to change all the Maplin AB12Z order codes into numeric equivalents :-)

Especially fun for Rs and Cs.

Although that might have come *later* than CashTEL, as DTMF phones weren't widely used but Maplin customers could build their own modem.

Owain