RT-11 idle light pattern

Paul Koning paulkoning at comcast.net
Fri Dec 29 11:45:15 CST 2017

> On Dec 29, 2017, at 9:16 AM, Noel Chiappa via cctalk <cctalk at classiccmp.org> wrote:
>> From: Paul Koning
>> Here's what it looked like 
> Not having RT11, I embedded this in a small stand-alone program (which took a
> little work, Unix assembler being rather different :-), so I could see it (it
> wasn't obvious from the code what it did).
> Pretty clever, to get that complex a pattern out of so few instructions.
> Although the self-modifying code is, err.... (If anyone wants the source or
> .LDA, let me know, I can post/upload it.)

Yes, a bit weird indeed.  Stranger still is the "fancy" lights in RSTS, also an Anton Chernoff creation.  "Fancy" because it produces a rotating pattern not just in the data lights which is easy, but also in the address lights.  It runs in supervisor mode, in versions of RSTS that did not use that mode for real work.


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