On Fri, 19 Jul 2019 19:16:09 -0700, Tom Brennan  wrote:

>Simple: No
>
>Longer: I'll guess you're talking about clearing memory?  I do seem to
>remember writing code on a z80 to clear a section of bytes to zero, and
>oops if I messed up it would keep writing zeros to 64K, wrap around to
>zero, and then continue on until the zeros hit the instructions that
>were being executed.  Everything but parts of the loop code was gone,
>and since x'00' is a z80 NOP, the processor would remain running - just
>not really doing much of value.
>
>On 7/19/2019 3:16 PM, Lester, Bob wrote:
>>
>>       Who remembers how to "ripple core" on a 360/75J?   Back in the day, I 
>> was taught that it "wrote un-digit zeros" to all storage locations (main + 
>> LCS) on the box.   If course, an IPL was required after this was done.
>>
>>       Not sure how widely it was used.   A simple yes or no is OK if you 
>> cannot provide details.    😊
>> 
In days of yore, was there a button on the console, perhaps white, recessed 
behind a
plastic guard to do something like that?

-- gil

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