Very Computer

I have a problem with the F030 blitter.
I want to use the blitter in non-hog mode while the CPU doing something else.
The idea is to set up a list of jobs for the blitter and interrupt the CPU
everytime a job has finished, start the next blitter job and then let the
CPU continue with what it was doing. To do this I need to know how to produce
an interrupt when a blitter operation has finished.
On the STE the blitter BUSY bit is connected to the MFP I/O bit #3, so it is
possible to let the MFP detect the state of the BUSY bit and produce and interrupt
if a change occur. However, THIS DOES NOT WORK ON THE FALCON! Why?

 /
/ Daniel

Quote:>I have a problem with the F030 blitter.
>I want to use the blitter in non-hog mode while the CPU doing something else.
>On the STE the blitter BUSY bit is connected to the MFP I/O bit #3, so it is
>possible to let the MFP detect the state of the BUSY bit and produce and interrupt
>if a change occur. However, THIS DOES NOT WORK ON THE FALCON! Why?

Well the obvious asnwer seems to be 'because the Falcon doesn't have an
MFP chip!'.
Although most of the MFP chips functions are emulated by the SCC, not all
of them are, for reasons known only to Atari. This is why MFPint() doesn't
work on the Falcon.

This may not be the reason however, just my suggestion.

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| {{{ Dan }}} |
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|>
|>
|> Well the obvious asnwer seems to be 'because the Falcon doesn't have an
|> MFP chip!'.

Wrong. The falcon has an MFP chip, but it is not connected to an external
rs232 port.

|> --
|> +-------------+
|> | {{{ Dan }}} |
|> +-------------+

--
       _______    _____          o           ____       Erling Henanger
      /___       /____/ /       /   /|  /   /           Norwegian Institute
     /          /\     /       /   / | /   |   ___      of Technology. (NTH)
    ------     /  \   /____   /   /  |/     \____| o    Oh well.

    |> Well the obvious asnwer seems to be 'because the Falcon doesn't have an
    |> MFP chip!'.

Quote:>Wrong. The falcon has an MFP chip, but it is not connected to an external
>rs232 port.

I stand corrected.
So much for what Atari UK told me then... :)
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| {{{ Dan }}} |
+-------------+

The Falcon DOES have an MFP.  It's just not used for serial I/O any more.  All
the other functions, including interrupt, and even the Ring Indicator input
are still there.  It's still used for timing signals in the Falcon.  Otherwize
every program that used interrupts on the Falcon would break.