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Old 08 February 2015, 11:52   #108

Psygore's Avatar
Join Date: Jan 2002
Location: France
Posts: 482
Originally Posted by Toni Wilen View Post
It has to work on real hardware because Lotus Trilogy Lotus III loads data to low part of 64k buffer and game won't work if loader also uses same buffer for CD DMA. Hardware always selects highest enabled and free slot when it looks for next buffer slot so if software is fast enough in decoding buffers, only few highest slots are actually used by the hardware.

Just make sure there is not too many overflow interrupts (all enabled buffers have been loaded and software didn't free any of them before new track comes), overflow requires restarting load command and I have no idea how long it takes for real hardware to re-seek.
Thanks for the info. Yes the 2nd disk of Lotus3 is loaded into the cd buffer, but I think it's unwanted from the coder as the loader still searchs in all the dma buffer for sectors (and he does a checksum of the loaded data to be sure that it's ok).

Btw is there a cd32 hardware reference manual ?
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