Date   : Fri, 10 Mar 2006 21:25:42 +0000 (GMT)
From   : Sprow <info@...>
Subject: Re: Mandelbrot plot times & host speedups

In article <20060310152550.22309.qmail@...>,
   Greg Cook <debounce@...> wrote:
> On Thu, 09 Mar 2006 19:03:12 +0000 (GMT), Sprow <info@...>
> wrote:

> > If I take out the line with the PLOT/MOVEs on it goes down to 43
> > secs, so the other 3 mins 50 secs must be spent waiting for the 
> > beeb to plot it.
>
> There were a couple of speedup tips in The Micro User, which will by
> some accounts drastically improve the host's processing rate:
> - September 1984, p.180. (Contributed by I.A.Padgett)
>   Longer intervals between keyboard scans.  The Tube-compatible version
>   is:
>   *FX 151,69,255
>   *FX 151,70,255
>   (The normal values are *FX 151,69,14 and *FX 151,70,12.) 

Saved 9s. It's not so much "longer intervals between keyboard scans" as
"anything hanging off the 100Hz tick is much slower". 

> - February 1988, p.89. Don't sample any ADC channels:
>   *FX 16,0

Saved 3s, and at least left the machine useable,
Sprow.