Re: [stella] 2P x 3 digit score routines?

Subject: Re: [stella] 2P x 3 digit score routines?
From: Thomas Jentzsch <tjentzsch@xxxxxx>
Date: Mon, 16 May 2005 03:22:51 -0400
Fred Quimby wrote:
> This looks interesting, but as it sits it looks like it would
> require digits to be stored in RAM since it uses absolute indexed
> addressing.

Yup. But that shouldn't be any problem for Andrew. Though by now I
don't think this code is very useful for him.

> What's the purpose of the TXS/JSR in the middle of the kernel, is it
> just to burn up cycles?

Nope, that's the key trick. By letting the stack point to RESPx, a JSR
triggers both RESPx very closely (1 cycle = 3 pixel) together. Else
the minimum distance is 3 cycles (9 pixel).

Have fun!
Thomas Jentzsch         | *** Every bit is sacred ! ***
tjentzsch at web dot de |

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