Fast RAM and f_read

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Foxie
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Fast RAM and f_read

Postby Foxie » Wed Apr 20, 2016 8:07 pm

I'm allocating fast RAM using GEMDOS m_xalloc ($48). Is it then permissible to use GEMDOS f_read ($3f) to load data from disk directly into fast RAM?

Obviously, the hardware itself cannot perform disk DMA into fast RAM. Does the operating system handle this by reading into an ST RAM buffer and then copying into fast RAM? Or is performing f_read into a block of fast RAM simply illegal?

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Cyprian
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Re: Fast RAM and f_read

Postby Cyprian » Wed Apr 20, 2016 9:30 pm

you can use f_read and TT-Ram.
In case of the TT and SCSI, data will be laded by DMA directly to TT-Ram, in case of the ACSI and Falcon's SCSI/ACSI data will be loaded by DMA to _FRB bufor in ST-RAM and transfer to TT-Ram by the CPU
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Foxie
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Re: Fast RAM and f_read

Postby Foxie » Wed Apr 20, 2016 10:56 pm

Excellent, thanks for the detailed response ^.^

Hopefully my routine should be TT and CT60 compatible now, though it's a bit tricky without owning either to test on ^^;


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