This circuit was found in a1980s Motorola documentation. The integrated circuit is from that time. The frequency depends on the crystal.
This high quality circuit with complementary symmetry was found in an Electronics World of 1966....
This circuit was obtained from an American documentation from the 1980s. The T1 triggering...
This circuit appeared in a noverber 1962s Practical Electronics. The magazine is no more, but the...