PDP-11 tape question

Jon Elson elson at pico-systems.com
Wed Jun 24 17:37:44 CDT 2020

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.


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