Hello, * On Fri, Mar 30, 2012 at 08:33:39PM +0200 Ingo Korb wrote: > Why do you expect correct operation when the hardware is broken? The "broken" here is relative - at least, we thought so. When ATN is asserted, the drive has to respond in a specific time frame. We thought that the ATN trap is only needed in order to make sure that the device reliably reacts in 1 ms. When the floppy enters the main loop again, it pulls DATA low and sends ATN ACK to inactivate the ATN trap. In the scenario presented here, the uZoomfloppy has exactly one floppy drive. It *knows* that the drive is there, and that it is exactly one drive. Why does it know this? Because the uZoomfloppy goes to the VIA chip directly, getting the data pins from that one. That's why there is no ATN trap anymore. So, because of the working of the ATN trap when ATN is asserted (put low), and the knowledge that there *must* be a drive ready, we thought the rules can be released, so the uZoomfloppy just has to wait indefinitely (not more than approx. 90s, that is) for DATA to go low, and everything should. Obviously, we neglected an effect when ATN is deasserted (put high again). Thus, we try to find out the reason of this effect, and if anything can be done about it. Regards, Spiro. -- Spiro R. Trikaliotis http://opencbm.sf.net/ http://www.trikaliotis.net/ http://vice-emu.sf.net/ Message was sent through the cbm-hackers mailing listReceived on 2012-03-30 19:00:25
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