On 06/24/2020 04:12 PM, Chuck Guzis via cctalk wrote:
On 6/24/20 1:23 PM, Jon Elson via cctalk wrote:
The 1052 Selectric console on the 360's were not on a channel, but
driven via direct I/O directly from the CPU microcode. (Yes, the
console has a pseudo channel address that made you THINK it was on a
channel, but it actually wasn't.)
One prank to pull on an operator was to write a CCW chain to ring the
1052 bell and then to a TIC back to the bell ring CCW.
At least on DOS/360, pretty much impossible to kill without doing an
IPL, as the keyboard would be locked.
Yup, the only way to stop that would be to do a halt IO
instruction or press system reset.
Jon
