On Mon, January 21, 2013 6:42 am, firstname.lastname@example.org wrote: > > On 2013-01-21, at 02:43, Pete Rittwage wrote: > >> Generally this looks like transfer/copy code from BurstNibbler. > > I believe that it is more or less generic approach used by many programs. > AFAIR burstnibbler and others used ATN line for handshaking, which I very > much prefer to avoid using. > >> The idea >> is if there is a delay in receiving the byte-ready signal, the hardware >> is >> probably waiting for a sync signal to end, so it sends a "sync" data >> byte >> back to the C64 (or drive RAM is extra RAM is used) every so often. >> This >> makes it easier to "write" this area back to the disk as a sync. The >> delays are cycle-counting to guess the actual sync length. This is also >> density specific, so these delays are usually runtime-modified. > > Hm - Not sure if I understand but I don't even spin the motor. I have no > disk in drive. I turn off IRQs. And the only thing I want to achieve is a > reliable (handshaken) data transfer, regardless of the timing. Just > transfer between CPUs. Right now it seems to be randomly corrupting the > data like if there were still some other factors affecting the states of > the serial lines. And since I already started to disassemble my DD3 board, > I currently don't even have the real hardware to verify this on and check > whether it is not only VICE's "feature". So this is existing code from something or is it something you are developing? I may have misunderstood- I thought you were asking about an existing technique you found somewhere.... -Pete Message was sent through the cbm-hackers mailing listReceived on 2013-01-21 14:00:03
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