From: Jim Brain (brain_at_jbrain.com)
Date: 2007-12-14 23:38:46
David Wood wrote: > I realize this would be slow, but relative to the speed of the IEC protocol, > why not swap bufferspace into and out of a couple reserved harddisk sectors? > I believe you'd still need a 512 byte sector somewhere, as you need to write the data all at once, not repositioning the IDE drive once you start (I don't think IDE can seek to a byte in the 512 byte sector. If it could, we could just do that. But, 1K of additional RAM banked in somewhere where there is no ROM/RAM/IO would work fine. You only need the 512 bytes during the write operation. The tricky part is updating BAM. How does the 1541 update BAM now? Doesn't it use the command channel buffer to read BAM into, update, and write it back prior to writing the new sector? As well, when you initially write out the sector, do you set next T&S to be 0,255, and then go back when you lay in another sector and update? Still, all of the operations require a reusable 512 byte RAM. Jim Message was sent through the cbm-hackers mailing list
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