[Coco] Re: Speed up and slow down POKE

[Arthur Flexser]

On Mon, 2 Aug 2004, Torsten Dittel wrote:

> > True but the loss of video on the 1 likely or 2 less likey but still
> > possible I always regarded as a failure and on the very earliest boards of
> > the CoCo 1 you could get other problems especially corruption of some RAM
> > although that would take a while.  I didn't like to leave a programme
> > running at full double speed and have the video go crazy.  This was never a
> > problem on a 3
> 
> AFAIR memory loss was taking place on all CoCo1/2 boards because the
> dynamic RAM isn't refreshed any longer while on "dope". However, there
> was some software using the mode (remember that great music program from
> the Rainbow playing tunes like "Axel F."?). The trick was to return to
> the "normal" speed at times e.g. in the vertical blank interrupt service
> routine to allow memory refresh).
> 
> Torsten
> 

My recollection was that the "trick" was that the memory would be
refreshed if you accessed it, so you just needed to make sure that the
memory you were using was frequently accessed.  No need to return to the
slow speed mode.

Art