On 05/05/2021 10:36 AM, Chuck Guzis via cctalk wrote:
As far as any "whine"--I vaguely recall hearing a high-pitched whine if I put my ear close to the power adjustment panel in a CDC Cyber--but it was barely audible.
The inverter whine on the 360/50 and /65 was completely insane, and the 2500 Hz output put the pulses from the push-pull SCRs at 5 KHz, near the ear's peak sensitivity. They had to lay out the machine room so nobody would have to be near it for more than a few seconds. The tape library and CE work area was back behind the CPU.
But, it was not really audible near the console. Jon
