Memory Clear/Set for PDP-8

[vrs42]

Today I stumbled across Frederick Kline's amazing contribution from 1968:

http://bitsavers.informatik.uni-stuttgart.de/pdf/dec/decus/decuscope/Decuscope_Vol07_1968.pdf

(pages 10 and 11) and updated the code here:

svn - Revision 5757: /trunk/pdp8/memclr

to include working versions. (One minor bug fix involving an ISZ that skipped and messed things up.)

I'm particularly astounded by the "set all memory to HLT", which I had previously not believed possible.

I think the technique would also work for any value, if the program were suitably relocated. (Of course, many values are not sustainable, since executing them will scribble memory.)

Vince

 

[daver2]

This was always the classic programmer challenge...

Dave

 

[thunter0512]

Today I stumbled across Frederick Kline's amazing contribution from 1968:

http://bitsavers.informatik.uni-stuttgart.de/pdf/dec/decus/decuscope/Decuscope_Vol07_1968.pdf

(pages 10 and 11) and updated the code here:

svn - Revision 5757: /trunk/pdp8/memclr

Thanks for the link to the entertaining article about the "night watchman" by Frederick Kling.
I tried the 8 word "Absolute Clear" sequence and it works nicely. I also tried depositing a single 2000 at a random location and got the nicely incrementing counter. Well done "night watchman".