ncoplin@orbeng.com wrote: > It looks like the following snippet is the key part of the JD routine, which > reads in data as bit-pairs every 10us. The trick of course is if this is to > be replicated for a VIC20 or C16/Plus4 then the data needs to be processed > in this relatively short time as there is no hand-shaking to hold off the > 1541 once the Ok for the byte send has been initiated. Also, data is sent as > 254byte packets... between pauses. Pauses? Maybe these pauses are used to work around the badlines on the 64? Somehow a 40us badline and a 10us timing don't work well together if the routine doesn't know when to expect a badline. The same could be used to work around badlines on the 264 series, only that you need a longer Pause (two badlines, I think), which will make the overall transfer speed slower. On the 64 ususally Sprites are switched off during fastloading to avoid extra memory accesses, but I don't know about Jiffy. Does the TED have any memory accesses except for video matrix and attributes, and refresh, of course? Nicolas - This message was sent through the cbm-hackers mailing list. To unsubscribe: echo unsubscribe | mail cbm-hackers-request@dot.tml.hut.fi.
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