On Fri, Apr 03, 2009 at 06:23:22PM -0500, Jim Brain wrote: > Along those lines, is there a document that describes the tape interface > from an electrical perspective. My AVR ASM is quite rusty, so the > C2N232 code is not making much sense to me. The read, write and sense can be mapped to GPIO. The C2N232 makes use of the input capture and output compare timer features, but that is not strictly necessary. It would be good to map CASS WRITE to a pin that can generate an interrupt. The motor voltage is not TTL but something between 6 and 9 volts. In the C2N232, this voltage is halved by a resistor divider (4k7+4k7 if memory serves). If possible, it could be good to use distinct I/O lines for sense, read and write on the pass-through port. (Just connect these lines in the AVR firmware, e.g., by using the Pin Change Interrupt.) If this is not possible or feasible, you should be able to connect the pass-through port in parallel. I'm not sure of CASS READ, though. You'd better check the schematic diagram of a tape drive. Marko Message was sent through the cbm-hackers mailing listReceived on 2009-04-04 18:14:53
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