Re: speed up the apple

[dempson@actrix.gen.nz (David Empson)]

Guillaume Tello <houten.van@wanadoo.fr> wrote:

> just a thought, I have a graphic card in my IIe, so I don't use the standard
> video output of the console.

Further details, please? What is this card?

If your "graphic card" is just generating RGB output then it is
accessing exactly the same memory areas in the Apple II as the built-in
video generator does to get the video data to be displayed.

> Is there a way to disable the video system of the IIe that could speed up
> the machine?

No. The video system also does the RAM refreshing, and there are many
other parts of the system (such as cards in slots and other built-in
I/O) which are dependent on the clock frequency being left alone.

Apple II accelerators have to bent over backwards to work with the slow
I/O clock: some work by replicating the entire RAM and ROM in fast
memory on the accelerator card, but then slow down to synchronize with
the real computer when an I/O access is required. Others work by caching
frequently used code or data, and reads operate at full speed, but
memory writes slow down and synchronize with the real computer, as do
all I/O accesses.

-- 
David Empson
dempson@actrix.gen.nz