Re: [cc65] C128 functions slow()/fast() for C64

From: Daniel Pralle <>
Date: 2012-10-21 15:40:51
On Sun, 21 Oct 2012 15:22:12 +0200
"Marc 'BlackJack' Rintsch" <> wrote:

> Hi *,
> Any thoughts about providing `slow()` and `fast()` functions for the
> C64 target that switch the screen on/off and would set a C128 into 1
> Mhz/2 Mhz mode?
> It is common to do this in computing intensive programs like
> compression software.  C128 users get some extra speed out of the C64
> application and on the C64 it doesn't do any harm AFAIK.  Even there
> you get a small speed gain because the VIC doesn't stall the CPU any
> more for memory access.
> Ciao,
> 	Marc 'BlackJack' Rintsch

Would be nice for Atari target as well. Display-DMA off increase speed
from 1.2 MHz to 1.8MHz.
To be precise, display-DMA steals cycles from 6502 that it effictivle
runs at 1.2MHz instead of 1.8MHz  :)

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Received on Sun Oct 21 15:41:07 2012

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