tops20 assembly tutorials

Rich Alderson RichA at
Thu Mar 10 13:17:43 CST 2016

From: David Griffith
Sent: Wednesday, March 09, 2016 4:14 PM

> On Tue, 8 Mar 2016, Rich Alderson wrote:

>> From: David Griffith
>> Sent: Monday, March 07, 2016 11:53 PM

>>> Specifically I'm trying to build and run this:

>>>          CIRC 2,-^D18

>> Where did this code come from?

> I got it from Jan deRie when I asked about it on a Youtube video[1] 
> showing the Panda Display in action.

Something just occurred to me.

Exactly *where* are you trying to run this program?  On a kn10-kl (the
extended KL-10 CPU defined by klh10), on a SimH KS-10, or on a real CPU
(KL, KS, or Toad)?

I just had a look at the klh10 sources and find that Ken Harrenstien
added the CIRC instruction to his KL emulation as well as his KS
emulation in 2002.  If you're running any klh10-based emulation, that
instruction ought to work.  It would only work on MIT-specific real


Rich Alderson
Vintage Computing Sr. Systems Engineer
Living Computer Museum
2245 1st Avenue S
Seattle, WA 98134

mailto:RichA at

More information about the cctech mailing list