BUBUNV bubble universe too fast

[Andrew Barron]

Hi, the Bubunv  'bubble universe' program in the ITS Lars directory executes far too fast. I have seen versions for other computers on YouTube that look much better.

Can someone who understands Midas assembly code please suggest how to delay the program loop so that it runs more slowly? I can do the edit in EMACS, but I don't understand the op-codes. It just needs a time-wasting loop, but I don't know where to put it.

Thanks

Andrew B

[Andrew Barron]

I changed the value of N=200. to N=1000. It improved the display a lot. It is less frantic. But the images are still drawn and decaying too fast.

[Lars Brinkhoff]

Sorry, I don't have any suggestions.  I converted the program quite verbatim.  I don't remember now if all parameters are the same as the original.  If anything, I would think it runs too slowly.  I would say displaying on the color scope is part of the problem.

[steve...@gmail.com]

A question could be whether the PiDP-10 is running throttled or not. If unthrottled, everything on the PiDP-10 would run unrealistically fast. Make sure that the SET THROTTLE <x> in SIMH is at a reasonable level? After using CTRL/E to drop into SIMH:

sim> SHOW THROTTLE -- will let you know what it is currently set at.

sim> SET THROTTLE <x> -- throttles the PiDP-10 to execute that many instructions per second. e.g., SET THROTTLE 800K will run 800k PDP-10 instructions per second.

sim> GO -- restarts the PiDP-10

Having found the right throttle setting, that setting command can be put into the boot.ini file to make it automatically set on start up.

Just a possible suggestion ...

Cheers,

-- steve

[Andrew Barron]

I tried changing the throttle. Actually, putting in pauses seemed the best. I ended up setting 400000/100. But overall it is not any better than the change I made to the loop. Time to move on, I think!